Along the bottom of the screen are four icons that, from left to right, open a 3D carousel, a favourite apps launcher, your contacts, and homescreen settings. The 3D carousel is a classic example of the sorts of interface mistakes made by not just these small software developers but the very makers of these phones. It presents you with (surprise, surprise) a carousel of the home screens and lets you spin them around to get to the one you want. It's of no benefit whatsoever.
Thankfully you can swap this to a grid layout instead - alike to the Leap interface on the HTC Desire - which is slightly more useful. As for the homescreen settings, you can change the number of home screens (with settings for both 'professional' and 'lifestyle' layouts) and choose whether the contacts and app launcher shortcuts show you 'favourites' or 'last used,' among other options.
In essence, MobileShell is just a fancy looking app launcher. Go beyond the homescreen and everything is standard Symbian with all the positives and negatives that entails. Nevertheless, it has a much nicer look and feel than the standard homescreen of Symbian and in having multiple homescreens adds a significant amount of functionality as well. You can switch to the standard homepage at the touch of a button, or have MobileShell only launch when you want so installing it isn't a be all and end all decision.
Both our 5530 XpressMusic and the N97 test phones ran MobileShell comfortably, providing a fast and smooth experience. The fluidity of movement when panning the homescreens left and right puts the standard Symbian interface to shame. Functionally it also provides a huge boost to both these handsets as neither has a multifaceted desktop arrangement. In contrast, phones like the Samsung i8910 HD and Sony Ericsson Vivaz do have some sort of multi-desktop arrangement so the case for MobileShell is less clear cut. However, in our experience the homescreens of these devices aren't very easy to use and aren't as configurable as MobileShell so you'd still benefit.
If you've invested in a top-end touchscreen Symbian-based handset and find its interface frustrating, you'll appreciate the additional usability that MobileShell provides. That said, £26.95 is definitely too expensive to our minds. Considering you can buy a full fledged sat-nav app for that much, spending that amount on software which doesn't add anything fundamental to the device is stretching it. Were the price to get closer to £10 we'd outright recommend this software but as it stands we'd be inclined to put the money towards a handset upgrade in the future.
SPB's MobileShell for Symbian provides a nice upgrade to the dour touch-screen interface that Symbian provides. Its multi-faceted desktop arrangement puts far more functionality in easy reach than standard Symbian and it looks significantly slicker as well. It is however too expensive at £26.95 and we'd prefer to see this drop to nearer £10 before it's an outright recommendation.