I have used W8 slightly less than 2 weeks on the laptof of my wife (she asked me to install linux instead). Like many, I have not liked the general UX, but what surprised me a lot is that to work around the bad UX, I have naturally started to learn the keyboard shortcuts. Many are identical in W7, but I did not need them before.
I think that W8 could be usable if we first learn all the important keyboard shortcuts.