If the N900 had been the same size as the N810 or *gasp* bigger (5 inch screen 1024 pixels), it would have raised the bar much more. The unfortunate thing was the shrinking to a smartphone sized device which causes it to be compared to smartphones and we can all agree that the phone functionality leaves some to be desired.

As a MID I have no doubt maemo 5 is the best current OS for that niche.