I'd love to see a comparison - the HD2 has some pretty impressive hardware, and there's been a few videos posted to support that:

http://wmpoweruser.com/?p=9905

The person filming opens one app after another and leaves them all running in the background, scrolling around in the GUI and opening new apps (including playing videos and navigation software) and the HD2 doesn't even stutter.

What would happen if you did this on the N900?