Sadly none of the linux desktop environments are particularly great either - unity, gnomeshell, and kde all have different problems and none of them are nearly as refined as the OS X UI. That being said, if you are comfortable with a minimal tiling wm like awesome or xmonad, you can have a very productive environment.
I second the suggestion of Awesome. It's really easy to set up your own highly customized window manager. The tagging concept is also really interesting, and I haven't seen anything quite like it in any other WM.
