Hey guys. I'm debating whether or not to sell my current iMac (24" 2.8Ghz, with the Ati 2600HD) and replacing it with the base level 27" iMac. My main reason for doing this would be the Video card (I may even wait until I can afford the one with the 4850) I'm just wondering how much of a speed boost switching would give me. As the 4670 would be compatable with OpenCL and stuff, would I see that much difference in Day-to-day activities? I also edit a lot of SD video, how much of a difference will I see in this. I game quite a bit too (in boot camp of course).... to make a long story short I suppose, how much better is the 4670 (and even the 4850), than the 2600? Thanks.