Yeah, it would be great if the modded versions of the game were on Macs. And by the way, I own a Mac, and Boot Camp running Windows, and no, my Mac from 2007 is never laggy. Never had a problem with it.
ssc4k Sounds like your build options aren't configured correctly, ensure you're including the necessary libraries for both, there's no reason why it shouldn't work.
I made a race with my recent laptop ( Windows 7 ) and my cousin's laptop old of 2 years ( Vista ). My laptop was closed and the other was open, I pressed the start button on mine and with the other clicked ( With Vista ) to open Internet. Guess what? I had time to open mine, and almost open Internet before Vista opened Internet. So if you ask me what I think, Vista : Lame, Mac : Good , 7 : Very good.
Noone asked for your opinion. What OS is the best is completely off topic.