With a growing roster of touchscreen mobiles, it's natural that Samsung's flagship Soul U990 sliderphone should incorporate an element of the latest high-end mobile must-have technology.

The premium Soul packs in a 5-megapixel camera and high-speed 3G HSDPA in a slimline metal casing, and is the first handset to sport Samsung's Magical Touch user interface. Rather than a full-function touchscreen, Magical Touch introduces a navigation touchpad that changes control options according to which functions are being used - a similar concept to the LG KF600's InteractPad system.

Magical Touch is effectively a touch panel replacement for a conventional navigation control pad, with set of control key icons displayed according to context - music player controls, camera buttons, directional arrow menu buttons, and so on. A slight dab of the touchpad activates the control, with haptic feedback (a slight vibration) to let you know the key's been pressed. As you change menus, the touch icons switch accordingly.

Despite its flagship billing, the Samsung Soul U900 doesn't pack in all the latest mobile technology. Its 3G HSDPA connectivity provides mobile browsing and download speeds of up to 7.2Mbps on networks that support these rates, but there's no Wi-Fi connectivity. It's not built around a smartphone operating system either, and doesn't boast GPS sat nav connectivity. It does though have a music player powered by ICEpower amplifier technology from Bang & Olufsen, and full web browsing capabilities.

Handling and design
The Soul follows on directly from Samsung's Ultra series of super-slim, highly pocketable mobiles, and has a suitably thinline 12.9mm profile to match. Its premium metal components bump its weight up to 112g, giving the phone a substantial feel which is reinforced by its large 105.9mm (h) x 49.5mm (w) footprint.

It's certainly a sleek and classy looking design. The Magical Touch pad sits below the main 2.2-inch display, a rich 16 million-colour QVGA (240x320 pixels) array. Samsung hasn't gone totally touchpad, like the KF600, instead including conventional softkey buttons plus call and end keys around it. This can feel slightly odd at first as you alternate between featherlight touch-sensitivity and proper pressing, but you swiftly get used to it.

With the Magical Touch pad to a large extent mirroring the changing functionality typical of a navigation D-pad, there doesn't feel a huge amount of functional difference between it and other touch sensitive control D-pads.

The icons do, of course, label shortcuts and options more clearly than you'd normally get on a standard navigation D-pad. For example when the music player or camera is activated, the usual D-pad controls and shortcut icons that would normally be illustrated on the screen are displayed on the touch pad. But with the majority of the menu system a familiar Samsung set-up, it's a useful rather than jaw-droppingly different approach. As a result, the Soul feels comfortable and intuitive to operate - it doesn't take much getting used to.

Responsiveness is always an issue with touch-operated devices; thankfully, Samsung has catered both for those who prefer a silky touch and those who like pressing harder, with an adjustable level of touchpad responsiveness. Still, there's always the possibility of inadvertent thumb-skimming activating a button in way that would be less likely to happen on a normal D-pad... Users can also adjust the Magical Touch pad's colours, with a spectrum of tones to choose from.

The Soul's metal and rubber-feel plastic construction makes it solid feeling and tactile. The slide-down numberpad is classy looking, smooth and responsive, with chrome curves adequately separating the flush large number keys. There's a dedicated video call button - a front-facing secondary camera for face-to-face calling sits above the display - and a button that allows users to switch quickly through open functions (texts, music player, browser, and so on).

Camera quality
There's a side button for firing up the 5-megapixel camera, but unlike the G800 (which also has an optical zoom) you can't use the camera with the slider closed, as its hidden behind the back panel. This makes handling less elegantly camera-like, with the numberpad exposed when shooting in landscape mode.

There's no optical zoom built into the Samsung Soul but with an onboard autofocus system and some sophisticated controls, it puts in a high quality shooting performance on its highest quality 2560x1920 pixels setting. The touchpad presents quick control buttons for four key camera options - macro mode (for close up shots), LED flash on or off, timer and exposure control - and the volume key on the side becomes the digital zoom.

On top of a wide spread of settings controls and adjustments, the Soul incorporates face detection technology to enhance autofocus performance with shots of people, a digital image stabiliser option to reduce the effect of camera shake, and Wide Dynamic Range gadgetry to improve shots in difficult lighting conditions.

Results from the camera are impressive. Shots are extremely detailed, and the 2-step autofocus and macro systems ensure you can get focus on the subjects you want, even at extremely close quarters. Colour rendition is vibrant too. Indoors shots in subdued lighting aren't so good, however, and the LED flash only provides limited improvement for low light shooting, and doesn't give a natural feel.

(You can see samples of shots taken with the Samsung Soul, and read in more detail about its capabilities in our article Samsung Soul U900 camera samples.)

While not quite as good as the best 5-megapixel shooters, image quality was still generally very high, even in reasonable lighting conditions. Post shooting, you can upload pics to blogs or social networking sites easily via an onboard Shozu application. There are some better than average image manipulation tools too for in-phone editing.

Video capture is limited to QVGA quality, and looks OK on the phone in full screen mode, although it's not particularly impressive on a larger PC display. Downloaded or streamed clips - quick to fire into your phone thanks to HSDPA - look fine on the screen too.

Music player
You can download music, too, of course, as well as loading up tunes from your PC using the supplied Samsung PC Suite Multimedia Manager software, or syncing to Windows Media Player 11, using the in-box USB cable. You can also copy tracks over in mass storage mode, or Bluetooth files to the phone. The Soul has 100MB of internal storage capacity, which can be expanded by slipping a MicroSD card into the side - cards of up to 8GB capacity are supported.

The user interface for the music player is tidy and attractive, with the usual selection of track categories and a decent amount of options for tweaking sounds and organising tracks. The Soul is another of Samsung's handsets to have ICEpower audio technology from Bang & Olufsen onboard, which promises good quality sound. A shame, then, that the earphones supplied are an average set; as the Soul uses a Samsung connector rather than a standard 3.5mm headphone jack socket you can't easily upgrade to your own headphones (unless you're using a Bluetooth stereo pair).

Sound quality is reasonable through the in-box headset, but we'd have liked to feel the full audio force of the B & O amplifier through high quality ear-wear. You could also try the loudspeaker, but sound quality through this is poor. The onboard FM radio is a useful extra option to tune into, however.

Changing themes
If you like trying out new themes on your phone, Samsung has included a whole bunch of options for changing the look and feel of the user interface. Its User Create Skins (UCS) set-up allows you to create your own customised themes by playing around with images, fonts, text, overlays, colours and so on. There are stacks of options and combinations to experiment with, enabling ambitious users to create some impressive, highly exclusive, themes on their phone.

Naturally, with 3G and HSDPA firepower, web browsing is swift on the Samsung Soul. It's loaded with a NetFront v3.4 browser, which provides a reasonable mobile browsing experience; you can switch between full web views or mobile-optimised small screen rendered page views, and zoom in and out of pages. Downloading the excellent Opera Mini browser application will boost the performance, however. An RSS reader application is also included, enabling you to get regular updates from favourite websites or blogs without browsing each time.

The Soul is geared up for the usual Samsung spread of office tools and productivity options. There's email support, with a document viewer to open attachments (or other files loaded onto the phone), plus calendar, memo, tasks, calculator, convertor and various clock functions.

Performance
With Samsung's quoted talk time of up to 4 hours, and standby of up to 400 hours on GSM networks or 250 hours on 3G, users should be able to achieve get a decent amount of battery life from the Soul, despite the added drain of the touchpad control.

We found call quality to be very acceptable, with decent reception that was plenty loud enough in the earpiece. The loudspeaker isn't the loudest, however, and you may want to use your own loaded music tracks for ringtones if you don't feel the Soul's are grabbing enough.

Conclusion
The Samsung Soul is an attractively designed handset that introduces another new take on touch technology for mobiles. The Magical Touch interface's functional similarities to conventional mobile navigation pads makes it feel familiar and intuitive. It adds a bit more to usability, with the controls changing in context with the applications being used, but Samsung doesn't overcomplicate it by trying to do too much. Its a tidy system.

As a premium flagship handset you might expect more from the Soul. It doesn't do GPS, Wi-Fi or offer smartphone feature customisation. But Samsung hasn't gone all-out to make the Soul a do-everything mobile, aiming it more at the premium phone buyer looking for a well crafted, stylish piece of kit.

Its 5-megapixel camera can be a fine performer (though not the best in its class), and its music player has some finesse, although the headset set-up could be better. HSDPA will come in handy too if you're looking for speedy downloads. It looks good, is comfortable to use and performs well, but its not the sort of must-have object of desire you might have hoped for.

Samsung Soul U900 technical specifications