I think it boils down to the large screen and slim form factor of the HD2, versus the N900's QWERTY keyboard, 32GB storage, more consistent interface, better camera, lower price and open source software.

I tried to make a comprehensive comparison chart, but it hasn't helped me to decide. Do I want to get a superb device that will leave me forever squinting, panning and zooming, and will bulge in my pocket? Or do I want to get a fabulous screen with my perfect form factor, loaded with an operating system that will make me feel dirty and compromised every time I use it?

Some people say "don't knock a 3.5 inch screen until you've tried it", but I know from the N800/N810 that many websites are barely usable for me on a 4.13 inch 800x480 screen.

Video demos always use sites like the NYT or the BBC which have narrow columns and can be double-clicked to zoom them into nice readability, but the real web doesn't work like that. You might need to view an 800-pixel-wide diagram, or a wide table (PayPal history, for example) where zooming is useless and you really want to be able to see the whole thing at once on a screen as large as possible.

Regards,
Roger