Windows 8 runs fast but has some serious problems,
1. The interface is not intuitive, you honestly have too look hard to find out how to shut it down.
2. I had more trouble with backwards compatibility then in seven, this is honestly not a big deal as I don't run many legacy programs but some of my GOG games didn't run as well.
3. hate the tile thing, I can see how it would be fine on a touch screen but I wish it would let me default to desktop view
the positives are:
1. on my solid state it boots in 7 seconds over 15 for windows 7
2. runs a bit better on Street Fighter, I can use x8 anti aliasing whereas before only x4
My end conclusion is that under the hood they did all the right things but I don't like the interface so it's hard for me too boot into it somedays.