We particularly liked Scenes, which allows you to flick between several different setups for your phone, each of them populated with different combinations of apps, wallpapers and widgets. 'Work', for example, puts your appointments front and centre on the home screen; but you're free to rename each scene and customise it as you wish.
The whole HTC Sense 4.0 skinned Android 4.0 experience is lag-free, and less gimmicky than previous incarnations - swirly 3D animations are no more. There's a notifications bar at the top of the screen, as is now pretty much standard on high-end smartphones, and the ring unlock system works well, allowing you to jump straight into a message or quickly take a picture.
It can still look a little cluttered at times - especially when compared to the Windows Phone 7.5 Tiles system or iOS 5 - with HTC Sense 4.0 occasionally offering up such an array of options and buttons that we worry it might confuse a novice smartphone user. A decent hints and tips system, overlaid on the main screen, goes someway to alleviating this though, and power users will love how much you can customise the One X. There's also some nice integration with cloud storage services, including 25GB of Dropbox space for HTC One X users.