I seem to be a lone voice in the wilderness but:
Windows 8 is, by far, the most resource efficient OS that Microsoft have released. It is a bit of a jump from XP or 7 (we won't mention Vista spit ) but it is really good once you learn how to make it work for you.
Windows 8.1 is out soon (NOT service pack 1 apparently) and they promise to restore the Start Menu, although, I quite like having a whole screen for the "start bar".
WyeDyed, using a desktop, Windows 8 x64
There, I've said it!