Samsung has hit upon a winning formula of slimline style and functionality, and there seems to be no stopping it in its quest to conquer the ultra-slim sector of the mobile market.

The company's groundbreaking Ultra Edition won it many plaudits, thanks largely to its wafer-thin proportions. Now, with the Ultra Edition II series, Samsung has refined the look to make the range even more desirable...oh, and it's shaved off a few more millimetres as well.

Sitting just above the original Ultra D900 flagship model, the quad-band U600 sliderphone moves away from the matt black of its predecessor and goes for a suitably understated blue-grey metallic shine that maintains an air of business-like sophistication.

It's even thinner than the D900, both in width and depth, and at 81g it's also 2g lighter, presenting a more pocket-friendly proposition all round.

Style is clearly foremost in Samsung's mind with the U600, and dominating the front of the handset is a mirror-effect LCD screen. Merging unobtrusively into the LCD are two touch-sensitive soft-keys, while the traditional red and green call and end keys have made way for a classier, all-silver look complemented by the simple circular navigational dial.

Slide the phone open using its smooth spring-action mechanism and the white backlit keys come to life, revealing a flush brushed-metal numeric keypad. In keeping with the handset's simple look, there's no definition between numbers and, unlike the soft-keys and call/end buttons, neither the keypad nor the four-way navigational dial is touch-sensitive - something that can take a while to get used to.

The interface itself is also more sophisticated than previous incarnations, which in turn tends to require a few more button presses looking for your desired function. Redressing the usability balance, though, comes a quick-access personalised menu and a nifty new Smart Search facility that allows you to locate files in much the same way you would do on a PC.

Once open, turn to the rear of the handset and you'll find a lens for the built-in camera, complete with self-portrait mirror and LED flash. Pictures can be taken using either the dedicated shutter button on the side or the central navigational key, before being stored either to MicroSD card or the phone's 60MB inbuilt memory.

Style and substance

Samsung has clearly realised that there has to be some substance to go along with the style, and the built-in auto focus camera sports no less than 3.2 megapixels along with plentiful control over settings like white balance and ISO, and a 4x digital zoom.

For those who like a touch of novelty, you can even take a photo of a business card and the Namecard Recognition feature will automatically add the details to your contacts.

Image quality has improved since the original Ultra Edition, but the auto focus is still a touch on the slow side meaning blurred pictures can be expected when shooting anything with a hint of movement. That aside, exposure, sharpness and colour reproduction are usually very good.

Video is also catered for, but with a maximum resolution of 352 x 288 pixels, the footage is no more than par for the course when compared with most mid-range mobiles.

The other big-hitter when it comes to current mobile must-have features is, of course, music, and Samsung has sent out all the right signals by equipping its new Ultra Range II with digital power amps developed by the purveyors of superior sonics, Bang & Olufsen.

The player itself caters for a wide range of file formats including MP3, AAC and Windows Media, and it's possible to create playlists both directly on the handset and when hooked up to a computer using the bundled PC syncing software. If you get bored with your tunage, you can always call into action the onboard FM radio instead.

Listening to music on the supplied headphones is actually pretty good, which is fortunate as only a proprietary connection is provided so you're stuck with them. Tonally, audio is slightly bass-heavy and lacks separation, but set against other mobile headsets it holds up well.

Support for A2DP stereo Bluetooth is also on offer, so it's easy enough to go wire-free with a set of Bluetooth headphones, or enjoy your music through your hi-fi if it's geared up for Bluetooth audio streaming.

As a standard GPRS handset, web browsing lacks the speed of 3G but is perfectly serviceable nonetheless, while a built-in email client means you can keep in touch with your Inbox as well. USB connectivity provides mass-storage support, and with Samsung's PC Studio software loaded you can sync and organise your files without any drama.

In terms of performance, the U600 immediately demonstrates the benefit of Samsung's new Optimized Power Usage Solution (OPUS) by managing around four days of standard use before the battery gave out - much better than the original Ultra Series. Audio quality on calls is second to none, and likewise signal strength is good, even in known problem areas.

Samsung has done an excellent job improving on what was already a quality handset - both in the design and functionality stakes. Even the interface manages to look more 'grown up', if a little longwinded, and if you don't mind the absence of 3G then the U600 is definitely worth a look. This is one stylish phone, and for once proves it's not always necessary to compromise on features in order to look good.