I've been running win8 pre-release for two or three months and I like it. I run it dual boot on the same desktop pc as a win7 partition, and it feels a bit slicker. I've read somewhere that there's been some optimisation of the underlying code so that may not be my imagination. Nice clean graphics.
The start menu seems a tiny bit pointless (or is it just a flat Start menu?) but hasn't got in the way of my using it. Some aspects I like, a few others take a short while to get used to (as with Win95, XP, Vista etc.etc.etc.)
I can't agree with anyone that Vista is better - Vista was just Win7 beta with all the bugs left in.