From a usability standpoint, Windows 8 seems to be one of the easiest full desktop OSes I've seen, the windows key takes to to a large icon screen with all of your programs, and you click on the one you want to run. I think that some of the decisions made to accomplish that goal hurt productivity for more experienced users, and those experienced users experience that as a hard interface. I had the same reaction when I had to use windows 7 after years of a tiling window manager and the terminal.