Playing CS:GO on Fedora 17 with the latest nVidia drivers is an absolute nightmare. However, the framerate and audio lag are doing wonders for building my patience.
Playing CS:GO on Slackware 13 64bit with old nvidia drivers is an absolute joy for reference.
I haven't been in the linux gaming loop in a while so pardon my ignorance here... are you using Wine or VirtualBox/VMWare or something else?
Probably Wine. Virtualization almost always prevents the guest OS from accessing the graphics card, which is very unsuitable for gaming.
A bit late of a response sorry, but now that VMWare and others have OpenGL support inside the VM, isn't that the graphics card access you are referring to? I'm sure it's still slower than bare metal, like all abstraction layers, but perhaps it's better now?