Well, I just upgraded from 8 to 8.1. Performance hit I saw in 8.1 preview is gone and I now get a slightly higher score with Windows 8.1. When I ran benchmark on windows 7 I got same score as windows 8, however windows 8/8.1 seems smoother; I'm not sure why. I still hate windows 8.1 UI behavior, however I think I can live with it till 8.2. I pin every app I use to task bar so I don't have to use the start screen. It's nice I can directly to desktop with 8.1.

Win 8.0:



Win 8.1: