Well, I guess it depends what you're most used to. I personally think that the GUI you get on Linux (Gnome in my case, but others too) are far superior to Windows (and OSX too, BTW):
* Magnetic borders for window management
* Focus follow the mouse (window management again)
* Virtual desktop (yes, OSX has it and some third party tools on Windows, but they're not as good as X's virtual desktops)
Each time I have to use a Windows machine, I suffer because of the usability of the GUI. (And the command line too, but I can't really blame Windows or OSX for having a command line that sucks - it's not important for their target demographic).