The HTC Touch Diamond lacks that extra sensitivity that makes the iPhone such a pleasure to fondle but it’s the closest any phone has come to matching its fluid UI. Its mouth-watering feature set make these niggles easier to forgive and, with the competition closing in fast, the 3G iPhone needs to pull out all the stops.

The HTC Touch Diamond is a nice phone with a better camera than the 3iPhone 3G and other extras that will help make it a good rival, as long as HTC is able to spread its new Taiwan price of £50 to other parts of the world.

The Touch Diamond packs in a lot of features and is a good effort by HTC to rival the iPhone's touchscreen usability while retaining the power and extensibility of Windows Mobile. But despite the hype, the Diamond is distinctly half-baked.

Granted, the Touchflo 3D works better than ever to turn Windows Mobile into a genuine phone interface. It hides the ugly-duckling Windows interface away successfully, and browsing the web on HTC's version of Opera Mobile is fantastic. But as a complete package, the Touch Diamond just doesn't convince. Not only does the build not reach the standard set by the iPhone or even the previous generation of HTC Touch phones (this is especially disappointing given the £400+ price tag), but the performance is laboured and the software not entirely stable.

The good: The HTC Touch Diamond has a cool 3D interface and a beautiful touch screen. The Windows Mobile 6.1 smartphone also offers Wi-Fi, Bluetooth, GPS, and a 3.2-megapixel camera.

The bad: The Touch Diamond is sluggish and call quality is subpar. The TouchFLO interface has a bit of a learning curve, and there's no expansion slot.

The bottom line: The HTC Touch Diamond offers much in the way of sex appeal and flash, and it's certainly got a formidable feature set. However, we hope HTC resolves some of the performance issues we experienced before the smartphone is released in the States.