Just been using Windows 8 for the first time this morning, as I upgraded a few days ago before the Jan 31st cheap $40 upgrade offer expires. Jesus Windows 8 is not good, I mean, what the hell were Microsoft thinking? Firstly it's ugly as sin, second they've hidden Shutdown in a very awkward to reach place, thirdly the "modern" and the "legacy" environments really don't interact fluidly and it's an unpleasant mix to have to use e.g. use a "modern" app and the thing throws the entire system into the "modern" UI which isn't obvious how to escape from back to sanity.
There are good points though. Firstly, you can get rid of the most stupid Win8 shite using a free program called Classic Shell (http://classicshell.sourceforge.net/), and that especially gets you back a reasonable easy to access location for shutting down the computer. Secondly, I must admit that the classic desktop UI, now being 1980s simple patches of single colour, is far far faster than before, so as ugly as it is, fair enough I do notice the speed difference. And thirdly, there are more than quite a few little fixes throughout which I must admit are very neat, e.g. you can now pause long file copies, or that the task manager has been completely refactored for the first time since Windows NT 4.0, that sort of thing. Oh, and booting in Win8 is about twice as fast as Win7, which is nice. And ... okay, it did upgrade my existing Win7 system flawlessly, though you'll have to dive into the User Manager to undo its "upgrade" of your NT user account to a Windows Live account (I need my NT account to authenticate to all my Samba shares) and you need to delete C:\Windows.old for which you'll need to reset its permissions to all access before you're allowed.
Still though, Windows 8 very much comes across as 25% finished. Not recommended, not unless you're a masochist.