Haven't used it or even seen it yet, really. But I've been told it has a lot of little features that are cool. For example, you can plug in a USB disk and use it as extra RAM. It has also been explained to me that it uses a lot of memory because unlike XP, when you start it up it pre-loads things like Office, etc. into the RAM so those things will load faster.

400 bucks seems like a rip to me, but it has already been completely cracked so if anything I'll probably just download it.