Our OnePlus One has just received a software update which should address some of the issues experienced in this review. We're currently going through the new software and will update this review with our findings soon.
The Google Nexus 4, the Google Nexus 5, the Motorola Moto G, and now the OnePlus One; this 5.5-inch bolt from out of the blue (well, China) joins an exclusive list of smartphones that offer an awful lot of smartphone for not a lot of money.
But having used the OnePlus One as my primary phone for several days now, I'm wondering whether it needs to be placed in a category all of its own.
Here is a device that rivals the HTC One M8 and the Samsung Galaxy S5 for raw specs, but at a cost of just £229, $299 (around AU$320). That's less than half the price of those aforementioned big hitters.
As such, much of my early time with the phone was spent warily turning it around in my hands, like some kind of mysterious artefact of unknown origin, not quite ready to believe what was being promised of it. There has to be some compromise here, right?
Well, yes there is. In fact, there are several. But it's staggering how small they seem when weighed against that double-take-inducing price tag.
Usually when a cheap smartphone boasts specifications that bloody the noses of the big boys, it's the design that suffers. It's far harder to make a solid, stylish, and hard-wearing mobile device than it is to throw in the latest off-the-shelf chip from Qualcomm.
However the OnePlus One is a pleasure to hold and to use. Okay, so it lacks the HTC One M8's gorgeous metallic sheen, and you won't turn any heads when you take it out of your pocket like you would with a golden iPhone 5S. But show me the phone that does.
The OnePlus One nevertheless feels great in the hand. It's primarily made up of a quality matte plastic shell that extends around the back and sides of the device. This isn't a unibody construction, and this rear panel can be removed for customisation purposes, but it's firmly fixed in place with minimal creaking or flexing.
There's a metal-effect plastic rim that separates this rear cover from the glass front, which cheapens the effect ever-so-slightly, but it's thin and unadorned. It does mean that the aforementioned glass frontage appears to stand out rather than melding into the body of the phone, but it's not an unpleasant effect.
All in all, it looks and feels like something of a cross between the Google Nexus 5 and theNokia Lumia 1520.
The OnePlus One is not a particularly slim or light device, but then nor is it an absolute brick. At 152.9 x 75.9 x 8.9mm, its dimensions make it only slightly larger than the Sony Xperia Z2, which has a smaller 5.2-inch screen. What's more, the OnePlus One is three grams lighter at 160g.
Of course, this is still a monster of a phone when you compare it to older or smaller devices. I always thought of my trusty old HTC One X as a bit of a beast, but the 4.7-inch phone feels positively dainty next to the OnePlus One. Meanwhile my iPhone 5S looked like a (rich) child's toy when held next to it.
I've mentioned it a few times now, but the OnePlus One's 5.5-inch display really is quite the specimen. At 5.5-inches it's bigger than both the One M8's and Galaxy S5's, though it has the same 1920 x 1080 Full HD resolution. Admittedly that makes it a little less pixel-dense, but with 401ppi I defy anyone to call it anything but sharp.
If you're thinking that OnePlus may have cut corners with the quality of this display, then think again. It's an IPS display, which means it's sharp and accurate even when viewed from an angle, and it's made by JDI, the company responsible for the One M8's excellent screen.
The default brightness seems a little weak, but crank it up and you'll get a picture that truly pops, with impressively deep blacks.
Perhaps the best illustration of this is to boot up the gorgeous Badlands game with its inky-black silhouettes layered over detailed amber backgrounds.
Around the back of the OnePlus One is the vaguely oblong black camera element that houses the lens and dual-LED flash. This has been allowed to jut out slightly, its flat surface peeking above the curved shell. I quite liked the effect, especially in concert with the funky OnePlus One logo situated below.
OnePlus has housed a tiny pair of stereo speakers on the bottom edge of the device - as held in portrait view - with two telltale rows of machined holes either side of the microUSB port.
Button placement is strong, with the power key situated two thirds of the way up on the right hand side and the elongated volume rocker opposite on the left hand side.
This is ideal for a device as large as the OnePlus One, as they always fall under a thumb or finger, whereas a top-mounted button would have required some finger contortion to reach single-handed.
OnePlus has also included permanent capacitive hardware keys underneath the screen, which proves to be a mixed blessing. There's a menu key, a home key, and a back-up key in that order. I found it very hard to see these keys, particularly in daylight, as they don't light up very much at all.
They're also mapped a little oddly by default, with multitasking set to an awkward double-tap of the home button.
On the plus side, you don't have to use these keys at all, and you can also remap the keys to your liking. We'll discuss the OnePlus One's impressive customisation potential in greater detail over the next few sections.
Just about the only glaring weakness of the OnePlus One's external design comes in the form of its SIM tray. It looks to be made of a cheaper, rougher form of plastic, and I found the access hole to be an absolute pig to use with my iPhone tool (which I had to use as the OnePlus didn't come in its packaging).
Indeed, it seems as if this SIM accessibility was a problem for whoever used the phone before me, as the hole had a tatty and worn look to it, like it had been hand-drilled with a Black and Decker and a cheap drill bit.
This is the only external sign that we're dealing with a new manufacturer's first attempt at a high-quality smartphone.
I'm always interested to learn which processor is powering a new smartphone, but the truth is that it rarely matters all that much. Modern multi-core processors are all capable of running the latest operating systems, multitasking, 3D gaming, HD video and more without breaking a sweat.
But in the OnePlus One's case, the processor type truly is a noteworthy spec. It's a 2.5GHz quad-core Snapdragon 801.
That's remarkable not so much for the performance it produces (which we'll discuss in the next section), but because it's the very top end chip in the Qualcomm roster.
Just to reinforce that point, it's the exact same chip that can be found powering the Samsung Galaxy S5, one of the most capable, and expensive, phones on the market.
We've never seen a device that provides truly class-leading performance for just £220 before. It's simply unheard of. Even though Google doesn't bother with things like profit margins on its hardware, it still had to charge to £300 when it released the Nexus 5 with (at the time) top-end hardware.
The other key feature of the OnePlus One is its operating system. Again, we'll go into the precise details of this in the next section, but the very fact that the OnePlus One runs on CyanogenMod is reason enough for special mention here.
Based on Android 4.4.2, CyanogenMod 11S is a popular open source custom firmware project that modifies and opens out Google's operating system. It's several steps beyond the usual heavy-handed manufacturer skin we're used to getting, and it's perfect for you tinkering sorts.
CyanogenMod is all about giving the power of customisation to the end user rather than forcing them to put up with excessive bloatware and a restrictive interface.
Previously you had to root your Android phone in order to install CyanogenMod - a relatively tricky and risky proposition only really suited to those with a little technical knowhow (and an expired warranty). The OnePlus One is the first ever phone to ship with CyanogenMod as the default OS.
I'm one of the first to complain when yet another Android phone ships with a nonstandard take on the Android OS, as they're invariably inferior to stock Android. But CyanogenMod is different. It feels a bit like Android in God mode, with a level of unprecedented granular control that's there if you want it.
There are subtle tweaks to the interface, but they're almost always tasteful and thoughtful rather than simply change for change's sake.
One obvious example is something we hinted at in the previous section. If you're not enamoured of the OnePlus One's fixed capacitive keys (as I'm not), or hardware keys in general, you can deactivate them and revert to the standard Android software solution. This means that back, home, and multitasking keys occupy the bottom section of the screen, sliding out of view where appropriate.
After all this overwhelming positivity, I feel I should point out a rather surprising omission. While OnePlus has gotten things almost perfect on the spec front, the OnePlus One is a little lacking when it comes to storage.
You only get 16GB of internal capacity here, which, once you've taken the 4GB or so required for the system and OS into the equation, doesn't leave a lot for apps, media, and photos. Of course, 16GB wouldn't be a problem if there were a microSD slot, but there isn't one.
It's one technical area in which the OnePlus One falls well short of its pricier rivals. Given that the device has evidently been pitched with Android enthusiasts in mind, we're more than a little baffled at its exclusion.
There is a silver lining though - the One Plus One also comes in a 64GB variant. And it's more good news in the pricing arena, as it'll set you back just £40, $50 more than the 16GB model. There's no huge price bump that you get with the likes of the iPhone when moving from 16GB to 32GB to 64GB.
It leaves me wondering why anyone whould bother with the 16GB option - just splash that extra bit of cash and you'll be set.
The other set back for the OnePlus is its 4G connectivity. While it does arrive with 4G capabilities, in the UK you'll only be able to take advantage of the superfast connection on two networks - O2 and Three.
That means if you're on EE or Vodafone you'll be stuck with 3G speeds, which is a bit annoying. The reason for this is the LTE chip only supports a selection of frequencies, so coverage will vary from country to country.
The OnePlus One's CyanogenMod software is, by it very definition, an amateur effort. But don't let that fool you.
It has significantly fuller-features and is more polished than the vast majority of Android-based skins I deal with from top handset manufacturers.
At a base level that's because Android has been allowed to shine through bright and clear. CyanogenMod's developers and custodians evidently realise that Google's OS is already a thoroughly refined and pleasant-to-use operating system, and that layering a bulky UI on top of it isn't just unnecessary - it's downright detrimental to the experience.
Pick up the OnePlus One and briefly browse through its home screens and app menu, and you won't notice a massive difference from the stock Android experience found on the Nexus 5. And that's a good thing.
There's that familiar dual drop-down menu set-up that enables to you access your latest notifications and a settings shortcut menu with a directed swipe. There's also a familiar multitasking menu that offers thumbnail shortcuts to the most recently accessed apps.
The default lock screen is a little different and, in dropping Android's radial app shortcut system, a little less useful to boot. But once again, you can change that back in the settings menu.
It's in the settings menu where CyanogenMod really shows its hand. You can tweak everything, from the function of the hardware buttons to the colour, pulse, and purpose of the notification light.
You can customise the hue, saturation, contrast and intensity of the display, change the nature of the pulldown notification menus, and switch to a different default font.
This level of customisation is never thrust in your face, and it never confuses the OnePlus One's day-to-day usability. It's all just there, tucked away in the bowels of the OS, ready to be discovered or ignored as you see fit.
Oh, and credit must go to yet another manufacturer implementing a double-tap to wake system. On such a large phone without a physical home button, it's a massive plus.
On the slightly negative side, I found that the OnePlus One's gesture shortcuts, which initiate certain functions by drawing patterns on the screen, were a little too easy to set off inadvertently.
On a couple of occasions I found that Google Music started playing my most recent track whilst putting the phone in my pocket or laying it down. This is done with a two-fingered downwards swipe, which seemed to be a little too easy to do during normal handling.
The same thing happened with the torch app, which flicks the camera flash on when you draw a 'V' shape on the screen. Again, it's easy to activate by mistake.
As is the case with most software features here, though, these two gesture shortcuts (along with the ability to jump to the camera app by drawing a circle) can be turned off in the settings menu if you find them to be over-responsive.
Because CyanogenMod has left the Android UI relatively unmolested, it feels extremely fast. And with that Snapdragon 801 CPU on board, backed by a generous 3GB of RAM, it is fast.
In my GeekBench 3 tests, the average multi-core score was 3050, which is a little higher than both the Samsung Galaxy S5 and the HTC One M8, both of which run on the same chip, but with only 2GB of RAM compared to the OnePlus One's 3GB.
Those impressive performance figures are shown in general use too. Everything moves along smoothly, whether you're gliding between home screens, watching HD videos, or surfing the web.
On the latter point, booting up the full TechRadar site took just six seconds. That's everything, including adverts, fully loaded up. Your average Android phone would take around ten seconds to achieve that.
If you're fearing that the OnePlus One's battery might be the thing to trip it up, you'll be pleasantly surprised. This is a phone with some stamina.
It's easy to see why. At 3100mAh, the OnePlus One's battery unit is more capacious than the LG G3 (3000mAh), Samsung Galaxy S5 (2800mAh) and HTC One M8 (2600mAh), and it only just trails behind the Sony Xperia Z2 (3200mAh).
It's a shame that you can't replace the battery, especially given that the rear cover is removable (with some effort). However, most people will simply be happy that they can venture out for a full day without worrying about being away from a plug socket for too long.
Sure enough, our standard HD video test yielded some strong results. Running a 90 minute 720p video with the screen brightness cranked right up left 83 percent left in the tank on average.
That's better than the One M8 and roughly the same as the Galaxy S5 and the iPhone 5S - two of the previous strong performers in this particular test.
In general usage, I was able to get a day and half out of the phone. That involved watching a couple of brief HD videos, playing a couple of games, dealing with a number of emails and SMS messages, and plenty of fiddling with the phone's options and menus - all with the screen brightness at its top setting.
I left it on in Airplane mode overnight during my testing period, which seemed to drain the battery by three or four percent come morning time.
It's a good job the OnePlus One has such strong battery life as standard, because CyangoenMod is yet to implement a battery saver mode. Such energy-sipping settings have become the norm on other Android skins, so it's a little odd that it's been omitted from this "everything but the kitchen sink" effort.
Of course, you can take the appropriate steps manually, such as switching off Wi-Fi, lowering screen brightness, and switching off push notifications. But a simple shortcut would have been appreciated here.
The essentials
One area in which OnePlus appears to have taken its eye off the ball with the OnePlus One is in its most basic function. To be brutally honest, it's pretty sub-standard as a phone.
While signal strength appeared to be strong enough during my test period, call quality proved to be consistently poor. I frequently make the same call at the same time to the same number every weekday lunch time, but here on the OnePlus One it was always way too quiet - even with the volume turned right up. What's more, the other person's voice dropped out altogether from time to time.
The volume issue was persistent across multiple calls to multiple people, though thankfully the drop-outs weren't anywhere near as prevalent.
Of course, voice calling is no longer the primary function of a smartphone, but it's still an important one. Here's hoping OnePlus can do something about it with a simple software update, and that it's not a hardware issue.
TechRadar raised the speaker volume issue with OnePlus, and a spokesperson said that it will be fixed in a future software update - fingers crossed.
Otherwise, the calling experience is pretty much classic Android 4.4 KitKat, with the same crisp Phone and People apps.
The same goes for messaging, with both the default Messaging app and Google Hangouts present. Once you've updated the latter, you'll be given the opportunity to make it your primary messaging app, which allows you to merge your SMS messages with Google's instant messaging service. It's flashier, but not necessarily more streamlined, so it's nice to have the option of the two.
CyanogenMod has wisely stuck with Google's own keyboard here, which offers intelligent words suggestions and a Swype-like joined-up-typing system alongside an intuitive layout.
It's everything you need from a modern smartphone keyboard, though as always with Android, other options are available on the Google Play Store.
One input method that didn't seem to work well at all was the OnePlus One's voice wakeup system. Similar to the Motorola Moto X, you can wake the phone with a spoken command - in this case "Hey Snapdragon." Here you can set which app or function you want to boot into, whether that's the default Google Now search, the camera, or anything else you can think of.
Unlike the Moto X, however, it doesn't work very well.
Even at the voice training stage, I struggled to get the three ticks necessary for the OnePlus One to learn my voice. I tried speaking from a variety of distances, in a variety of quiet locations, and using various enunciations of the key words. But I couldn't get through the training process without repeated retries.
Once completed, the phone wouldn't respond to my commands. However it did, on several occasions, wake up to a random sound.
One time seemed to be when I'd made an extended hissing sound (I forget why), and another was when the phone was sat next to my laptop while I was silently typing out this review. Very strange, especially when you consider that saying "OK Google" and conducting a voice search from within Google Now seems to work pretty well here.
I've already mentioned that web browsing on the OnePlus One is an extremely zippy experience, and it's also a pleasant one thanks to that 5.5-inch 1080p display. You'll still need to do a bit of panning and zooming on content-rich web pages, but not nearly so much as on, say, the iPhone 5S.
There's good news and there's bad news when it comes to the OnePlus One's camera. The bad news is that it doesn't take as good pictures as the Samsung Galaxy S5 or the Nokia Lumia 1520.
The good news is that it's a £229/$299 phone, remember? And when compared to something equivalent like the Nexus 5 or the Motorola Moto X, it takes very decent pictures indeed.
Those two mid-range champs utilise 8MP and 10MP snappers respectively, whereas the OnePlus One boasts a 13MP unit.
Its Sony Exmor BSI images sensor and f/2.0 aperture also knocks the Nexus 5 (which is arguably the OnePlus One's most direct rival) camera out cold.
Of course, the proof of the camera is in the taking, and my test photos showed up a reasonably capable camera.
There are annoyances in basic usage, such as the positioning of the lens right at the top of the device, which means you have to hold it in a slightly unnatural pincer grip if you're to avoid getting your fingers in the shot on landscape snaps.
I also picked up on a general sense of sluggishness between pressing the shutter key and the OnePlus One's camera taking the snap, which seems to be attributed to a slightly ponderous auto-focus system.
But the results are quite pleasant. Images taken in good light were sharp, with fairly accurate colours. When focusing on nearby objects, they really tended to pop with detail against the defocused background.
Even daytime indoors shots were decent enough, avoiding that excessively murky and desaturated look that you find on many lesser smartphone cameras.
There's a reasonably effective HDR mode too, though there's a familiar sense of falseness to the resulting pictures, and one or two strange marks on areas of extreme brightness.
CyanogenMod has its own custom camera interface, and it's pretty intuitive. In particular there's a nice mode select system that involves swiping up and down on the main viewfinder, which is how you select HDR. Alongside this and the default Auto, which should have you covered for most situations between them, there are 10 additional shooting modes.
These range from Smart Scene, which appears to actively switch to the appropriate scene for the current conditions (if it detects a lot of movement or low light, for example), to the self explanatory Steady Shot, and through to commonly used filters like Aqua and Sepia.
You also get three permanent shooting control circles along the right hand side of the screen - one for pictures, another for video, and a third dedicated control for panoramic shots.
Along the left hand side you have four additional controls. One switches to the 5MP front camera, while another is for flash control. A third provides branching manual settings menus for things such as white balance, a timer, and additional shooting modes.
There's also a settings control here if you want to delve into image sharpness, ISO settings, burst modes and touch focus duration.
It's not quite the dauntingly comprehensive camera interface of the Samsung Galaxy S5, but then again nor is it the overly simplistic stock Android effort found on the Nexus 5.
Video is 1080p Full HD, as you might expect. It's pretty crisp and smooth, though the sound pick-up seemed a little harsh. Playback of that sound seemed to be pushed entirely through a single sound channel, another issue that will hopefully be fixed in a future software update.
With the level of hardware that the OnePlus One has at its disposal, you'd expect it to be a decent media player. It doesn't disappoint.
Whether you're watching 1080p video, streaming your new favourite album, or playing a GPU-stretching game the OnePlus One handles it all with almost dismissive ease.
That's not to say that OnePlus or Cyanogen has added any particularly noteworthy media bells and whistles here. But that's because Android is already perfectly well stocked for such things.
At the heart of the experience is the Google Play Store, which forms the brightly hued hub from which you can purchase movies, TV shows, MP3 tracks, ebooks, comic books, and games.
A while ago Google broke this Google Play Store down into its constituent pieces for convenience purposes, so you get separate Play Movies, Play Books, Play Newsstand, and Play Music apps alongside the main app store.
Google Music, of course, goes well beyond being a simple MP3 store. Sign up to Google Play Music All Access and you'll get a Spotify-like unlimited music streaming service.
There are tens of thousands of tracks to choose from, and you can even download albums to your device to save on data costs, or to ensure uninterrupted playback.
Even without signing up to the All Access service, you can upload 20,000 tracks from your own physical music collection to Google's servers, enabling cloud-based playback on any device.
I mention this because Google Music is the default music app on the OnePlus One, just as it for the Nexus 5. It's very good at what it does, too, offering a quick and intuitive interface that shows off high definition album art without feeling cluttered.
It's been worked into the CyanogenMod interface well, too. When playing a track, the default lock screen features a shortcut widget for playing, pausing, and skipping tracks, along with artfully blurred background album artwork that expands and sharpens as you complete the unlock gesture.
There's also the typical widget present in the notification menu from the homescreen, meaning you're never far away from your music on the OnePlus One.
When it comes to playing back your own video content, you can choose to do so through either Google's own Photos app or CyanogenMod's Gallery app. Google's effort is cleaner and less fussy, but the other option is perfectly decent.
The latter also includes additional audio effect options when playing video back. You can boost the bass or add a 3D effect, though I didn't pick up on any discernible difference from my own test samples.
No matter - the sound quality through a decent set of headphones is exemplary. It's rich, detailed, and with ample bass. Just don't rely on the OnePlus One's external speakers for watching movies or gaming, as they're weak, raspy, and they lack stereo separation.
Speaking of gaming, this is one of the best Android phones I've ever used for the task. That 5.5-inch 1080p display shows off everything with optimal clarity, which is especially evident on vibrant 2D games like Plants vs Zombies 2, Rayman Fiesta Run, and Badlands.
Crucially, the screen finds a sweet spot between visual fidelity and control. Take a complex multiplayer first person shooter like Blitz Brigade. The OnePlus One's display is large enough and sharp enough to minimise the effect of your two thumbs getting in the way, but is small enough that you can wield the device and reach the touchscreen inputs comfortably.
And of course, such demanding 3D games run well here, thanks to the OnePlus One's Snapdragon 801 CPU and 3GB of RAM. The handset does run very hot when it's put under strain by advanced games, but that's not uncommon.