Stumped when M asked me what is the difference between Windows 7 and Vista, when you look at it?!
Speed is definitely the main difference I felt, between the two. W7 is MUCH faster to start up - less than a minute - Vista takes AGES. Same applies for Microsoft Apps as well, especially EXCEL. But then again, it could be that it's on 64-bit. Also, speed can be relative thing, even though for a gizmo-insensitive guy like myself, the change in speed from 7 to Vista was quite palpable.
It was 12 midnight in the office, so I rambled something about the gadget bar in Vista not being customizable, until I found a site that taught me how to modify the registry to get rid of it. Talking about trivial lolx
Anyway found this more thorough comparison: