Based on the Tytn II handset from HTC, O2’s XDA line-up includes some pretty impressive models, and the XDA Stellar is the first to include both built-in GPS and a Qwerty keyboard.

Satellite navigation is taken care of by Copilot Live 7 software, included in the package, while Windows Mobile 6 drives the phone.

Measuring 20mm thick and weighing 190g, the XDA Stellar will be too bulky for many, but if you want a Qwerty keyboard you’re going to have to make some sacrifices. Slide the screen to the left, and the keyboard is revealed. With such little space between keys, typing is awkward at first and most definitely a two-fingered operation only. The tilting screen makes it perfect for sitting on a table to watch video.

Windows Mobile 6 can’t match the iPhone’s interface for ease of use, but it beats it hands-down in terms of features. Mobile versions of Word, Excel and Powerpoint are included, along with Outlook, Messenger and Windows Media Player. It can be slow to respond at times, though.

Battery life isn’t great and under pretty strenuous conditions it lasts just over a day. Used sparingly, you should get a couple of days out of it.

Copilot Live 7 works well, but it’s slower than a dedicated sat nav, especially when browsing the map while zoomed out. It houses most of the features you’d expect to see (including traffic updates), but although the walking mode will ignore one-way streets, it isn’t intelligent enough to direct you through parks.

If you can cope with its size, the XDA Stellar offers plenty, but don’t expect to type lengthy documents. It is also available through Orange, T-Mobile (as the MDA Vario III), with the cost depending on contract, and Sim-free for around £450.