First time I saw Windows 8, I was horrified. It looked utterly awful and I couldn't imagine myself using it on a day to day basis.
However, due to a drive failure, I installed it and thought I'd give it a shot. Once you get past the Start Screen/Page/Menu thing - which is what 99% of the fuss is about - it's not all that bad at all. It is a dogs breakfast though, and does need some refinement. However I haven't had as much fun finding out new stuff in an OS since I got my first OSX box in 2002.
Firstly, I'm currently using it for development on a multi-monitor setup - 3x 24" monitors with one in portrait mode. Windows 8 handles multiple monitors in desktop mode much better than 7, no question about it. The ability to have the Taskbar setup to display programs running on that monitor is a great change.
Secondly, The desktop environment is much cleaner and I'm glad the huge hive of junk that was the Start Menu has gone. The number of times I aimlessly trawled through it to find some obscure program I needed wasted way too much time... Now, I can just pull up the search and find whatever app, then either run it or pin it to the Start Menu/page, or the Taskbar.
Performance is better too. Simple stuff is a lot faster than 7, and running the whole OS from a new 256GB SSD means I can boot in around 12 seconds. Even spindle to spindle file transfers are a lot faster.
You might notice I haven't really mentioned Metro, well that's because I hardly use it. In my view, it feels like a 'fun layer' that you can almost shut out completely when using the desktop for serious stuff. Today I've used it precisely once as I pin all my apps to the Taskbar in pretty much the same way I use the OSX dock. That said, the live tiles are very nice and some of the news and informational apps are good. Overall though, the ecosystem is lacking in content and I really can't see any point when I'd use a Metro app alongside the desktop.
As far as shutdown goes? Simple, I just map the power button to shutdown and don't have to fiddle around in Metro for it.
So, while not a 'fan' of the extreme changes in Windows 8, I am glad I can shut them out to a degree, and can benefit from the underlying changes made to the desktop. It's by no means a Vista though. While I may not like Metro, the underlying OS is solid and works better than Windows 7.