Sony Ericsson's first Windows Mobile device is intended as a do-it-all business handset, with quad band GSM, HSDPA 3G and Wi-Fi keeping its connection options fully open, and with a slide-out QWERTY keyboard and large touch screen to make best use of its messaging and browsing capabilities.

It looks pretty good too, in black with a silver stripe around the sides. The large 800x480-pixel, 3.1in touch screen takes pride of place on the front, while beneath it nestles a rather messy cluster of control buttons around a touch-sensitive 'optical joystick' which acts like the track ball on a laptop, as well as a standard D-pad.

Great keyboard

It's a fairly hefty device, though there are certainly chunkier models with a slide-out QWERTY keyboard, and fortunately the keyboard on this one is better than most. It slides out with a reassuringly solid clunk and angles slightly upwards as it does so.

This is Sony Ericsson's 'arc slider' which is presumably meant to make the screen easier to read but while it's a flash looking trick, it doesn't seem to accomplish anything you couldn't do better by twisting it in your hands.

The keyboard itself however is very good – all brushed metal with four lines of well spaced, slightly angled keys. The screen automatically rotates into portrait mode when you slide out the keyboard too.

Problem Panels

Like many recent Windows Mobile handsets, the OS is initially hidden behind a proprietary manufacturer's interface and in Sony Ericsson's case it's the 'Panels'.

Our model came with seven of them, each offering quick access to one or more of the X1's functions, such as date and time, media player, FM radio, Google and more, with others available to download from the Sony Ericsson site. They look pretty good and work very well (except the Google one which automatically opens Windows Explorer rather than Opera, which is also available – why?).

The only problem is that it takes a few seconds to switch between panels, which slows down the navigation process. You can use the Windows menu of course but for this you'll almost certainly need to unsheathe the stylus and use the phone two-handed, which can become a hassle.

The browser is a pleasure to use however, though it's much better to surf with the keyboard open and the screen in landscape mode. You can sweep web pages around by brushing the screen with your thumb and zoom with the volume keys – mobile internet the way it should be.

Standard camera

A-GPS is on board, powered by Google Maps, which is pretty good as far as it goes and found our north London pied à terre pretty much instantly. It won't give you voice guidance though, but this being Windows Mobile you've got a very good choice of Sat Nav apps that can, including TomTom, Wayfinder and Garmin.

The camera is a little disappointing as it's 3.2 megapixels, just as we're getting used to having 5 megapixels on our fancier phones. It doesn't disgrace itself though, offering pics that compare favourably with similarly specced cameraphones.

There's an interesting addition with 'touch focus', which allows you to select the focal point of your pic by touching the screen. You can create some interesting forced perspective shots this way.

Basic music player

The music player has clearly been inspired by Sony Ericsson's Walkman range though it doesn't have the same breadth of features. There's no graphic equaliser and only a limited range of filing options.

The headphones too aren't Sony Ericsson's best, though they're not at all bad.

Fortunately there's the option to upgrade to your 'phones of choice via the 3.5mm jack plug on the top.

Onboard software

Windows Mobile 6.1 comes with a host of additional apps including Office Mobile, which allows you to create Word and Excel documents, though it will only allow you to view PowerPoint docs and PDFs.

Battery life wasn't overly impressive (though it rarely is on juice-hungry smart phones). Ours lasted a little over a day with Wi-Fi on, though there is a range of settings to manage the power drain.

The Xperia X1 is a pretty good smart phone overall, but not quite the iPhone killer we'd been hoping for. Consider it if you need a good browser and full range of connection options, but there are better phones for media playback.

Network availability: O2, others TBC

Looks: 4/5
Ease of use: 3.5/5
Features: 4.5/5
Call quality: 4.5/5
Value: 3.5/5