On the other hand from what I read,
XP - good
Vista - Bad
7 - good
8 - bad
10 - good
11 - bad
I don't have any experience in any of those so I'm not how true it is, but if it is, I guess hope that 12 will be out by EOL of 10?
And each 'bad' always brings to it a horrible UI change. Vista brought the window manager and those weird transparent windows and was generally ugly and buggy. Win 7 cleaned up the UI and made it flatter and simpler.
8 brought a full-screen start menu (!!). 10 went back to a 7-esque vibe (mostly).
11 is where we are.