See my comments above. I really don't think that any difference you might see would be enough to warrant a switch from BootCamp. If you don't think the Steam/Mac version plays well enough then the Campaign edition will not satisfy you either.
I have a Mid 2010 13" MBP with 320M GPU. I tried loading up a 1945 AD end-of game save from the GOTM community (Science victory). Standard map size, 8 civs, 18 city states. I have left Civ5 in its default minimum graphics mode. Unfortunately, I am currently running a new version of OS X that shall remain nameless on this Mac, so it may not be totally representative. However, just moving around the map is painful - animations are somewhat jerky; you can watch the tiles repaint one at a time when you scroll around ... Full screen seems better than windowed, but I wouldn't want to play a modern era game on this rig.
I have a Mid 2010 13" MBP with 320M GPU. I tried loading up a 1945 AD end-of game save from the GOTM community (Science victory). Standard map size, 8 civs, 18 city states. I have left Civ5 in its default minimum graphics mode. Unfortunately, I am currently running a new version of OS X that shall remain nameless on this Mac, so it may not be totally representative. However, just moving around the map is painful - animations are somewhat jerky; you can watch the tiles repaint one at a time when you scroll around ... Full screen seems better than windowed, but I wouldn't want to play a modern era game on this rig.