Get ready to smile.
1. The Speed
Windows 8 feels lighter and faster than any version of windows - ever. Microsoft has gone through a lot of effort to ensure Windows is optimized for performance. The technical underpinnings are a bit complicated (and if you like long blog posts, by all means check out this doozy from the Windows Team Blog (part 2, part 3), but doing things like hibernating the kernel on shutdown means things like booting Windows has gone from 30 seconds to 10.