I've been using Windows 8 since the consumer preview and I have to say that I hate it.

I installed the RTM over a month ago (got it from MSDN) and I still hate it.

Let me count the issues:

-- two versions of IE
-- jarring switch between desktop and metro
-- fullscreen ONLY metro apps
-- start screen full of garbage after installing apps
-- unintuitive menus
-- longer mouse movements and more clicks to accomplish most tasks (such as shutdown or control panel)
-- touch UI doesn't work for mouse/keyboard
-- additional security features that will drive you crazy. try linking to an office 365 account. It will try and take over your PC
-- no way to exit metro apps
-- removed media center / media player - have to pay extra to put it back in
-- Microsoft requires OEMs to use UEFI/Secureboot

I tried to get used to it for months - usually with new OSs, I come to tolerate or like it after I force myself to use it for weeks on end. But not Windows 8. The more I use it, the more I find to dislike about it. I wouldn't recommend it to anyone for desktop/laptop use. But I'm sure it would be wonderful on a tablet or phone.