So, on a hardware front, if you're not too concerned about its size, the HD2 has a heck of a lot going for it. However, as always, there's the software to consider and here the HD2 is a bit of a mixed bag.
Performance is something we certainly can't complain about. The Snapdragon processor at the HD2's heart makes mincemeat of any task you put it to, making this phone very slick in operation. We only had the phone for a short time and so didn't test it with games or other demanding programs, but in general use and when multitasking it was flawless (we'll be producing a video review soon, so you'll be able to see it in full flow).
HTC has also gone to town with its implementation of the Sense UI, revamping all its icons and menus to make them even bigger, shinier, and fancier to suit the enormous screen. Possibly the best demonstration of this - and it's unfortunately rather difficult to capture in still photos - is the weather animation that is activated when you turn on the phone. When raining (as it was at the time), you get animated clouds and rainfall in the background while rain drops will cover the inside of your screen until a windscreen wiper appears and wipes it all away. Of course it's a total gimmick but it is rather impressive and does mean you get a full and accurate description of the weather without needing to read anything.
It's not just the weather app that feels slightly gimmicky with HTC's Sense interface either. We've used it on many iterations of Windows Mobile phones and have always found it to be more showy than practical and this largely hasn't changed. In particular, the sliding icon bar along the bottom has never felt intuitive. Then again, with the limitations of Windows Mobile, even in its current 6.5 (Phone) version, it does well from a limited start. Also, if you get tweaking, you can customise it to be a bit more streamlined and a bit less fluffy.