I just installed Win 8.
Its super fun, smooth, elegant, quick and makes sense once you get to learn it.
I didn't know what to think and was totally against the Metro UI the moment I first heard about it. Now I love it.
Things to note.
UAC can't be turned off and if you do the registry trick to turn it off you can't use apps. However, you can turn off the annoying notifications but it doesn't disable it.
Think of the Metro UI as the Start>all programs (which is essentially what it is). The fact that it takes up the whole screen is actually a good thing. They've replaced buttons that lead to menus with side screens that pop out when you go to the side of the screen and metro apps close when you drag em down which isn't bad but can be frustrating when your used to hitting a red x your whole life.
Its well worth learning Win 8 IMO.
Sent from my PC using chrome.