I've been trying to find comparisons but could use some assistance from the macrumors people! I want to move over to an imac, but currently use a custom built PC with a geforce 560 ti 448 core vid card. From what i can tell, the 780m in the imac is better, but i cant get a firm grasp on HOW much better (both in mac and bootcamp'd windows). Anyone have an idea? my guess is roughly 25% better....does that sound right?