I know this is a weird suggestion, but the best combo for me is a Macbook (air or pro) with Parallels running a Linux VM full screen.

Performance is shockingly good, you don't have to worry about drivers, and you still get access to a bunch of nice OSX things inside the VM (Retina res, keyboard shortcuts for volume, Mountain Lion's speech dictation, etc)

Plus, you get that sweet sweet Apple build quality.