As to why I bought it, I was promised a smartphone from my results. I found the iPhone unnecessarily pricey, and had a look at HTC Android phones as I wanted apps and HTC had a good reputation from my peers. I was thinking of the Desire Z because of the physical keyboard, then the Desire HD for the larger 4.3 inch screen (as opposed to the 3.7 inch screen), then finally the Sensation (after some self-debate) due to the 1.2 GHz dual core processor (as opposed to the 1 GHz single core processor).
This should get me through a few years at uni, depending on Moore’s law and the price of baked beans.