The Engadget
preliminary review of the Diamond (I know different phone but they are similar) gave me some concern:
"Talking about user input for a moment, we were bothered with just a hint of lag throughout the system, which made tapping on things and entering text vaguely frustrating. It's possible that HTC could fine-tune this with a future firmware release, but we're guessing that TouchFLO 3D combined with the high resolution are pushing that 528MHz Qualcomm core to its hairy edge."
This is with WM6.1.