DESIGN AND BUILD

The One is an object of rare beauty: its comfortably curvy aluminium body with diamond-cut edges and reassuring weight make it a handset you’ll want to show off. It's almost perfect, it's only the Beats Audio logo round the back that might put you off.
Slim plastic strips outline the two integrated antennae, while speaker grilles top and bottom give the One a dose of retro charm. You can't swap the battery or slot in a microSD, but we think the ingot-like build is fair recompense. Hands down it makes the best impression of the current crop of flagship Android smartphones thanks to a design that Apple wouldn't sniff at. 
That said, with only 32GB on board and no expansion slots, storage is an issue. Get yourself a Spotify Premium account straightaway or you've got no chance. 

SCREEN

This is the best screen we've ever seen on a phone. Really. It's 4.7in and 1080p, giving it a ridiculous 468ppi – but that's only half the story. Colours are vibrant but not over-saturated, whites are pure and unlike the Sony Xperia Z, which really suffers when tilted upwards, movies look superb at any angle. It's super-sharp, using an SLCD display as opposed to the S4's PenTile, making for crisp text too. 
We prefer the HTC One's colour palette to the Samsung Galaxy S4's options (none of which nail it) – between the HTC and the Sony, it's a closer call. The Z can look more natural at times but blacks could be richer and as it's a 5in display, this – together with the rectangular design – makes it harder to hold one handed.

SENSE 5

The One runs HTC's latest Sense 5 skin above Android Jelly Bean 4.1.2 and we like it. It drops the multi-tasking button in favour of a double-tap of the home button, which is a neat touch, the 3D carousel has been ditched for a clean grid of open apps and there are plenty of clever new features like BlinkFeed and Zoe (see below). Overall it's a big win for HTC. 
Some of the icons are a little low-res and clownish, but extra features, such as power features in the People app, are easy to ignore if you don't want clutter. And though the One might be waiting for a few features only found in the latest 4.2.2 build of Jelly Bean (as seen on the Galaxy S4), none are deal-breakers. 
You'll want to make some tweaks to Sense 5 straightaway. We'd recommend swapping your app drawer to a 4x5 grid to make full use of the space and, if you plan to use the built-in keyboard, unchecking foreign languages in keyboard settings to avoid changing to French every couple of words. 

PERFORMANCE

This is a ludicrously quick phone running as smooth as an ice cream-powered Merc. With an EE 4G SIM inside (and, of course, coverage) web pages appear instantly, while the One's quad-core Qulacomm Snapdragon 600 chip tears through multi-tasking, Android games and Google Maps’ satellite view. It's almost entirely lag-free, as you'd expect and the HTC has showed no signs of slowing down during our testing.  
For number crunchers, the HTC One did very well in the usual benchmarks too. Excellent grades include a score of 2678 in Geekbench 2 and an onscreen score of 3573 frames at 32fps in GL Benchmark's Egypt HD test (besting the Xperia Z and Galaxy S3). The One also scored a speedy 1411.4ms in SunSpider's Wi-Fi browsing benchmark making it faster than the likes of the Nexus 4 which limped along with 1885.4ms.


BATTERY LIFE 

Battery life is only average – in normal use we found the 2300mAh battery will last a day, less for power users. The Power Saver and Sleep Mode will be your friends here but unlike the Sony Xperia Z you can't whitelist apps, like email, to keep updating you even when everything else stops pulling in data.  
So which are the main culprits for draining juice? Zoe, for one, is best left alone if you're worried about lasting the day but Sense itself needs a fair amount of power too. Plus it's best to stick a brightness toggle on one of your homescreens. 
For the record, the HTC One lasted just over eight hours in our video rundown test on medium brightness with Wi-Fi on, a SIM in place and no power saving activated. That sounds impressive but as we said, the One will need overnightly charges. There is a £45 HTC External Battery Bank, which contains a 6000mAh battery, available too if you find your handset is dead by 5pm every day. We'd also recommend the excellent Mophie Juice Pack for HTC One at £90 which will double the One's battery and gives it some extra protection too. 

BLINKFEED

Think of BlinkFeed as an oversized Flipboard widget. It pulls in image-heavy news stories from partners and your social networks to stream down one of the homescreens. The choice is limited for now – so there's a chance your favourite media outlets won't have signed up yet – but that should change soon.
Either way, it’s an energetic alternative to Windows Phone 8's Live Tiles. It delivers personalised news – including a Stuff.tv feed – in some style, although all those internet goodies may become an overwhelming welcome for some. If so, just move them over a page to the left of your regular homescreen. 

SENSE TV/IR

In the app drawer you’ll find TV, which, once you’ve selected your Freeview/Virgin/Sky sub, pulls in programme guide info – though it's not that pretty. You can also set up the One to control your TV and home cinema kit via the power button which doubles as a handy IR blaster. A stunner of a smartphone and a universal remote? Yes please. 

SOUND

The symmetrical BoomSound speakers ensure your movies and games are accompanied by loud, powerful sound. With headphones in, sound is punchy and detailed, if not quite as weighty as the likes of the Nexus 4, but certainly an improvement on the Galaxy S4. Beats Audio – as ever – is best avoided.

CAMERA

The UltraPixel gamble (fewer pixels but larger in size) has partly paid off, as HTC has equipped the One with a very versatile rear cam: it captures accurate colours, is superb in low light, has lots of fun filters and Zoe (see next section) means you won’t miss action shots. 1080p video is also impressive, but stills don’t stand up to being blown-up as well as those from some rivals and you can't zoom far compared to the Galaxy S4. More than fine for Facebook uploads and 4"x3" prints though.
HTC has also rolled out an update to its UltraPixel camera, improving detail and pumping up colours so that they're not always 100% true to life but look gorgeous. Still, based purely on camera the Galaxy S4 would be the phone we'd take out with us: it's light and easy to set up shots with and shoots the sharpest, cleanest video footage out of the three top Androids. 

HTC ZOE

Zoe (as in 'zoetrope') really gives your gallery some soul – by turning it into a set of Harry Potter-style living pictures. By capturing footage and extra snaps (20 to be exact) before and after each shot, you can scrub through the moment post-Zoe to pick the best frame – it’s seriously handy.
Unfortunately, it also results in a rapidly-expanding collection of photos, Zoes and videos which could end up in your gallery being a chore to keep under control. Be careful with Dropbox auto-uploads here too – it can get chaotic.  

VERSUS SONY XPERIA Z

The Xperia Z has a more relaxed colour palette for watching flicks, some of the best audio skills we’ve heard from a phone and crazy waterproofing. But the Sony’s angular chassis can be uncomfortable for some (unlike the perfectly formed HTC) and the viewing angles are less impressive than those of the always-stunning One screen. For most gadgeteers, the One comes out on top – for more spec and feature comparisons of the Xperia Z and HTC One, read our Versus.

VERDICT

The Nexus 4 showed us how Android should be done and the Xperia Z gave us full HD and a sleek – waterproof – build but until the HTC One we'd never really fallen for an Android phone. Until now. The One takes the customisation of Android, the liveliness of Windows 8 (in BlinkFeed and Zoe) and the premium styling of Apple to create a very special smartphone indeed.
So despite a mighty onslaught from the Galaxy S4, the One is still the phone we'd buy. For storage and camera (just), it's the S4. For media and waterproofing, go for the Xperia Z.
But for everything else – using apps and games, browsing, messaging and sheer pride of ownership, it's the HTC One. It's the most desirable Android handset ever, running more slickly than any rival and with a screen that makes us swoon.