Just to be clear, these complaints aren't arising because "Macs suck". The Mac client is just beyond atrocious.

I have the Mac client (ARR/HW bundle), as well as the Windows client (ARR only).

Running the Mac client at 1680x1050 resolution I was getting about 10-15 frames per second. Sometimes up to 20.

Running the Windows client, in Windows, running in a Parallels virtual machine ON TOP OF OS X, I was getting 30-35 frames per second at 1920x1200. (So I'm STILL in OS X, but running an entire virtualized Windows environment as well -- not just a wrapper.)

Something is very broken.