Ok I have done a little reading and am alittle confused. What is the main difference between the 1d mk3, 1ds mk3 and 1d mk4 and what are the benifits over a 5d mk2? I am not looking to upgrade, but just wondering. I know they have better iso range and af focusing and has higher fps, but is that it? And just for fun, would you trade your 5d mk2 for either of the mk 3's?

