Installation is quite simple, however getting the drivers (most of which are BETA) is a bit painful.
The best feature I have found so far is the mouse-over on the active windows on the task bar.
I dont recall Vista having anything like this?
When you mouse over an application the task bar, the thumbnails of the windows popup, and when you mouse over one of the thumbnails, all the other windows become transparent except for the moused-over application's window.
I think that is a great feature!