Chinese newcomer OnePlus is back with another attempt to marry top-level specs with a knock-down price, and it's come up with the company's best handset by far. It's powerful, it's sleek, and it should have the bigger manufacturers looking over their shoulders.

OnePlus appeared on the scene with its first handset in 2014, followed up by last year's OnePlus 2 and the even more budget-friendly OnePlus X (which now looks to have been discontinued in most parts of the world). While mostly well received, the phones haven't been without their issues (including the invite you needed to buy them), and with its third flagship OnePlus is looking to set down a new marker.

First of all this is a fine-looking phone: It's curved and contoured in all the right places, smooth and comfortable to the touch, and just 7.4 mm thick (down from 9.9 mm last year). It's not quite as gorgeous as the likes of the Samsung Galaxy S7 or the iPhone 6S, in my eyes at least, but it's definitely on a par with phones such as the LG G5 and Nexus 6P as far as looks go.

The aluminum unibody OnePlus has gone for this year feels great in the hand and it's one of those phones that compels you to pick it up and have a play around with it. The square, raised camera lens is the only moment of inelegance on the whole device, but overall the engineers at OnePlus have done a fantastic job on the design.

There's even – wonder of wonders – a physical mute switch, as there was on the OnePlus 2, something sorely lacking on the majority of Android handsets these days. Bizarrely though it seems to have come at the expense of the Do Not Disturb software toggle switch available in stock Android and we would have preferred to have kept both options.

Speaking of software, the OnePlus 3 runs a lightly skinned version of Android Marshmallow called OxygenOS, which OnePlus develops itself. There are thankfully very few changes from stock Android and hardly any bloatware apps – just basic Gallery and Music apps, plus a file manager that's actually pretty useful.

While its software may look a lot like a Nexus phone's, though, one thing you shouldn't go into this expecting is a Nexus-like update schedule to Android Nougat. Last year's OnePlus 2 didn't get the Marshmallow update until about a month ago, despite the software launching in October.

Back to the hardware, and there's a physical home button that doubles as a (very fast) fingerprint sensor, plus two capacitive buttons (soft physical keys, embedded in the bezel) that we grew to like. I find that it's easier to navigate around Android when the navigation buttons are lifted outside the display, even if you lose some screen real estate along the way. You can also reprogram them from the default functions (or even opt to use onscreen navigation buttons instead).

You can't swap the back plate, as you could with the OnePlus 2, but you can order official slim cases from OnePlus that give your phone a different look. Bamboo, black apricot, carbon fiber and rosewood are among those that are available.

OnePlus' whole approach is flagship specs at mid-range prices, and the innards of the OnePlus 3 really do compete with the very best phones of 2016: a Snapdragon 820 processor, an impressive 6 GB of RAM, a 3,000 mAh battery and 64 GB of internal storage (it's the only storage option and there's no microSD card slot).

Perhaps the biggest compromise comes with the 5.5-inch AMOLED display, running at a Full HD resolution of 1,920 x 1,080 pixels rather than the QHD 2,560 x 1,440 standard that can be found on most of the OnePlus 3's rivals. It's perfectly fine, but you do notice the extra sharpness and space if you put it side-by-side with a QHD phone.

Considering the price, we see this as by no means a deal-breaker, unless you're a keen gamer or someone else who really values as many pixels packed in as possible.

We should mention there has been some controversy over the color tuning used on the OnePlus 3 display, as it deviates from the standard sRGB. It didn't particularly ruin our time with the phone, whether watching movies or sending messages, and an update to enable manual RGB tuning is on the way OnePlus says.

Considering that the OnePlus 3 comes in at around half the price of competing flagship phones, these are very small sacrifices to make. You're still getting yourself a fast, powerful, good-looking phone and saving yourself a lot of cash along the way. We've been using the OnePlus 3 for a week or so and it's been a pleasure to use. Apps and the OS are snappy and responsive, calls and audio are clear (there's one speaker at the base of the handset) and the little extras (like that mute switch) are mostly welcome.

The phone comes with a 16-megapixel camera and a stack of extras: optical image stabilization, auto HDR, dynamic de-noise and phase detection autofocus (a staple of more expensive DSLR cameras). Despite all those extras, the custom camera app is fast to launch and simple to operate.

Photos are, on the whole, very impressive. Even in low light, the OnePlus 3 stands out, provided you keep very still (check the attached gallery for samples). Unfortunately (due to our review units living on a different continent) I wasn't able to compare it directly with the current kings of low-light shooting, the Galaxy S7 and S7 Edge and HTC 10, but we suspect it doesn't quite usurp Samsung's or HTC's phones (partly because the OnePlus camera lens has a narrower aperture).

Visual noise or artifacts aren't usually a problem and all the photos we took looked sharp, with good color balance and contrast (despite a week of rainy, overcast weather in England). Yes, it can stumble at times, and low light photography requires a steady hand, but this is a smartphone camera after all, not a DSLR or mirrorless.

We do like the manual tweaking mode hidden away that lets you adjust shutter speed, white balance and ISO speed yourself, and there's also the option of 4K video recording if you need it. Otherwise, just point and shoot, and you'll usually get great results.

Battery life is largely impressive too, with the OnePlus 3 regularly having plenty of juice left (20-30 percent) at the end of an average, medium-use day. Of course battery performance degrades over time on virtually every smartphone, and we've only had it for just over a week, but that's still worth noting.

In the official Gizmag battery test, where we play a 60-minute video at a set brightness (measured by a lux meter), the battery level dropped just 9 percent from a full charge, which beats the HTC 10 (11 percent) and both 2015 iPhones (13 percent) while being on a par with this year's Samsung flagships. That's one advantage of a lower-resolution screen.

The weather wasn't great when this shot was taken, but the OnePlus 3 camera keeps a lot of detail and captures color accurately(Credit: David Nield/Gizmag)

A fine macro shot from the OnePlus 3 with plenty of detail(Credit: David Nield/Gizmag)

Indoors and in darkness the phone understandably struggles a little bit, but still gets good shots, if you can hold it steady(Credit: David Nield/Gizmag)

Bringing back NFC (which was absent from last year's model) means it's Android Pay-ready, while the USB-C port and bundled cable offer a quick charging solution OnePlus is calling Dash Charge. From nothing, we found the battery level back up to 50 percent within half an hour and fully charged after less than 80 minutes. There are two SIM cards slots as well, if you need them.

Perhaps the OnePlus 3's biggest feature, though, is its price: US$399 unlocked. That figure shifts the needle from the phone being a strong contender to being one of the best choices for Android fans – or smartphone buyers in general – on the market. Sure, the Galaxy S7 and HTC 10 are better, but are they around $300 better?

There are other options of course. With another Nexus looming, the Huawei-made 6P can be yours for less than $400 nowadays if you can live with 16 GB of storage (you probably can't), but its specs are distinctly 2015. Last year's OnePlus 2 is now also a great value at $299; the new Moto G4 cuts back on the specs but also cuts the price in half. Whichever way you slice it, though, the OnePlus 3 hits a terrific balance point.

In previous years there has been a feeling that buying a OnePlus phone for a cheap price means a trade-off in other areas – not least the tedious invite system for getting in line for a phone. In 2016, with better specs, a great design and camera, and no need for an invite, there are barely any compromises left to talk about.

Okay, the screen and the camera aren't the best in the field but they're still very good. There are other minor issues (it can only support LTE on AT&T and T-Mobile in the US, for example, and you have to pay everything up front), but you're getting an awful lot of phone for the money.

OnePlus has finally hit the bullseye: a top-end phone at a mid-range price. And no caveats.

Product page: OnePlus 3

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