Okay i am planning on gettting a mac and after a ton of research i have narrowed it down to the Mac Pro. Now I will be using it for fcp, and stuff. Now i would like to know is a 2.66 and the 2.8 ghz really make a difference? I mean really big one i know that the 2.66ghz only goes up to like 2T all together for HD space and 16gb ddr and the other is 4T and 32gb.