I see Vista characterized as a failure over and over again, and Win 7 as a success. Win 7 is somewhat better than Vista, but the distance between them isn't that great. Besides the fact that UAC prompts were more frequent in Vista, was there some particular problem with Vista?
For a year or two there I was running workstations with both, and didn't see much difference.
I think Vista took the heat for imposing security where none existed.
It's the little things that add up, Vista is like Win7 with an itchy wool sweater over top. Win7 refined UAC, the quicklaunch/taskbar is amazing and the running task previews actually work, the start menu app search is better, the system tray notifications can be more finely tuned, and it runs significantly better on mid/lower end hardware.
I ran both Vista and Windows 7. As far as I was concerned, in terms of usability they are both pretty much the same as long as you turned indexing off on you Vista drives.
Do you feel like Vista ran slower than 7? That was my issue with Vista, the new design was fine, but it just seemed to run poorly compared to the speed of 7.
For a year or two there I was running workstations with both, and didn't see much difference.
I think Vista took the heat for imposing security where none existed.