My problems with vista started immediately upon installation.
It took nearly 4 1/2 months for proper SLI support to come from a combination of nvidia driver updates and microsoft updates.
I think this was the key to Vista's failure. Personally I never had a problem with it, but then I have never installed it on an older machine. I got it factory installed on a new machine - and there were no problems. This approach has always worked for me in the past - I don't upgrade to a newer OS, just replace the PC (not when the new OS comes out, but when it's time to replace the machine) with whatever OS they happen to be installing at the moment. But lots of people tried to install it on their existing machines - and got into lots of compatibility problems.
Windows 7 was the first OS that I installed on an existing machine. That was that Vista machine. Vista is still there, but I hardly ever use it.
Finally, for the similarity with Macs ... There is one particular feature of Macs that I can't accept - there is basically one toolbar at the top of the screen that changes its content depending on which window is currently active. Windows themselves do not carry toolbars, just some close/minimize buttons. This is the show stopper for me - I will not willingly use a Mac until they change that (which is probably never). Therefore I do not agree that Windows 7 looks like a Mac.