Initial shock at the size and featureless front and back of this imposing monolith soon turned to admiration. It's big and extravagant, but its chassis is a little more rounded than the Xperia Z's, making it easier on the hand than the angular older model it usurps.

The cool, rounded aluminium edges, chunky power button and glassy back just about give it enough character to make it loveable, once you've come up with a suitable method for holding it without stressing about dropping the slippery thing. We've already scratched the back up a little through gently putting it down on tables, mind, so it's one that might require a little care to keep in pristine condition. And given its £600 price tag, you are going to want to look after it.

And as for the performance, the high-end processor powers the Z1 extremely well, with nothing in the way of noticeable slowdown or trouble, even when updating apps while opening and closing tools like a multitasking madman.

We liked

The 1080p display is impressive. Video playback is fantastic, colours are deep and the images clear. Your own photos look great on the screen, the icons are sharp, web text readable.

This even trickles down to things like the camera, with image previews on the viewfinder appearing incredibly sharp and lifelike.

The camera is, for the most part, one of the best any company's managed to squeeze into a phone. Outdoors it performs extremely well, managing bright days, gloomy contrasts, sunsets, movement and more with ease.

It's only when indoors in poor light and without the flash that there's some noticeable noise on shots. 1080p video is smooth and effortless, too.

It is definitely waterproof. We chucked it in the sea lots of times and it still worked. The sound recording quality gets a bit muffled until the water dries off, but we suspect that might be what happens to all camera mics when you rudely throw them in water, so won't mark it down for that.

Touch screen responsiveness suffers a little when phone and fingers are soaked, but after a few tries it usually responds.

We disliked

Sony's desire to push its other services is a little grating. It's nice having a free trial of its Music Unlimited service, but the way it demands credit card details to activate it, and sets renewals to "on" by default in the hope you forget to cancel, isn't great.

We've just committed £600 to buying the phone, must you try to gouge another £5 a month out of us?

This mass of Sony services all come with disclaimers and agreements to click before initial launch, plus Music Unlimited needs to regularly sign in.

Once a day you click on the Music Unlimited widget to play a song, and are told there are "No songs available" - which actually means you have to open the app and sign in to make it work again.

We're also, confusingly, going to mention the screen here. In certain situations - watching video, looking at snaps - it's excellent, and as rich and deep and colourful as you'd want. But the viewing angles are awful at times, the white balance miles off the likes of the HTC One, LG G2, Samsung Galaxy S4 or the iPhone 5S.

It's an odd thing to see, but Sony certainly cannot claim that its screen technology, of which it's tooting a fair bit thanks to lumping in a load of Bravia tech, can compete with the best the smartphone world has to offer.

The camera sensor is positioned right in the corner of the phone, so we found we'd quite often end up with fingers and bits of hand covering parts of the shot.

We're also massively uninspired by some of the performance levels of the camera - indoor specifically was not what we were expecting from a camera that promises to be as good as a high end compact. It's not terrible, but if you're buying the Xperia Z1 solely on its ability to take brilliant snaps anywhere, you'll be sorely disappointed.

It's a phone where you have to come up with your own special way of holding it when snapping, lest a pink blob mask the top-left corner of all your magic moments.

The speaker being at the bottom of the Z1 is a mixed blessing. It means there's no change to volume levels and audio quality when putting it down on a table or chucking it on the duvet, which is nice, but when viewing media in landscape orientation it's a bit distracting that the majority of the sound seems to come from off to one side. And resting it on a finger or thumb now muffles the sound instead.

Verdict

The Xperia Z1 is another all-round great phone from Sony, just like the barely-out-of-short-trousers Xperia Z it replaces.

It has a superb display at times, a large battery that easily sails through a day of hardcore use, and one of the best cameras we've seen on a mobile phone for both stills, 1080p capture and clever AR and live streaming toys.

Problem is, so was Sony's Xperia Z which launched just seven months ago and is now available on much cheaper contracts than the Z1.

For a premium price of £599 it's hard to recommend buying the Xperia Z1 outright if you're already a Z owner, when it's basically a spec bump in a slightly more premium case.

However, if you're due an upgrade or are made of money, there's a lot in this package in terms of performance. The Xperia Z1 feels sturdy, is powerful enough that it won't be outdated at the end of a two-year contract, plus it's sleek and big enough to turn heads - although some of those heads might be turning to laugh as you try to manhandle such an enormous slab of extravagant phone hardware.

The Xperia Z1 is a powerful, luxury executive toy for those who have to have the biggest and best, regardless of whether they actually need it or not.

It's a Range Rover for the school run. A gold toilet seat. Having all the sport and film channels on a telly in the shed. You'll feel awesome with one in your pocket, but for an all-round device, it feels like Sony has dropped the ball on design and screen technology and gambled too hard on camera and screen tech - a move that didn't pay off fully.