I have all three in my possession now and have spent much of the day comparing these three. Will have some test photos up soon, using the 5Dc first then the Rebel XTi later.
I will say this......the 70-210 F4 really does live up to the "Poor Man's L" reputation when you stop it down to about 6.3. The 70-200 F4L IS goes without saying, but the 80-200 kit lens is surprisingly tack sharp, loud AF be damned. The 10mm extra reach on the 70-210 F4 makes a difference on a crop format sensor though.



