I originally had picked up the 70-200 F4 IS. I thought this was the sharpest of the 70-200's and had the nicest contrast IMO. The only problem was the F4 and missed a lot of shots because of it.
Wasn't too happy when i got the original 70-200 2.8 and ended up selling it soon after.
After reading what all you guys had to say about this lens i went out and bought it. All i have to say is OMG. I find it as sharp as my 200 2.8 and the IS on this lens is amazing.
Thanks you all for helping me choose this great lens. Amazing!
5D-2 Mark ii 


