I never really understood why everyone was so down on Vista. Once I tweaked it, it was very responsive and loaded as fast as XP on the two machines on which I ran it. My Windows 7 64 startup and response times are the same as Vista 64, so I'm not really seeing any of the performance gains people are talking about. I'm dismayed that my show desktop button is now in a very inconvenient place and can't be moved. And I am also dismayed that the Ctrl+Up One Level button functionality, which I use constantly in XP, was not restored after disappearing in Vista.
Now, I will also say that I "upgraded" from Vista to XP twice. My reasons for doing so were fairly simple... XP did everything I need it to do while Vista failed to do several things that I required, such as run VMware server. Yeah, I know there is a tweak that you can do every time you boot up that will make it work, but that was too annoying.
I saw Vista as a fairly unnecessary release. Maybe things needed to be upgraded on the backend, and that's all well and good. But I found it bothersome that MS changed so many menus and locations and whatnot that most users were very familiar with. Most users don't want to take the time to learn a new OS--They want something they're familiar with. I don't care that MS says it's more intuitive--What's intuitive for most people is what they already know.
That said, I have mixed feelings about Windows 7. Unless I can get VMware running in it (which I have yet to do), I have a feeling that my upgrade isn't going to be from the RC to retail, but rather back to good ol' XP.