[Kurtz79]

I was able to play quite a few games (Civ5, Walking dead, Portal 2, Diablo 3) without any issues on a Macbook (Pro 15 Retina first generation). Portal 2 and Walking Dead are quite playable also in my Macbook Air 13 (2010, last model with nvidia board).

Of course these are relatively low requirements games. Do you have examples where the performance difference is relevant, and the games actually unplayable ?

[lazerwalker]

On my mid-2012 11" MB Air, most games around the level of requirements you said tend to run maybe 3/4ths as well in OS X as in Windows 8 (Portal 2 being a concrete example). Not unplayable by any means, but the performance difference is substantial enough that it's worth my while to reboot into Windows.