Your right flake :-) The sigma 8-16mm I'll admit is very nice & the distortion can be fixed. I have been using the 5d mk ii extensively on models :-) did a Photoshoot. So how you listed the uses was dead on.
When I used my sigma 150-500mn I could actually see how soft the images were at 500mm (stopping down didn't help) then I used the 100-400mm L wow big difference, though i'll admit they make good primes though :-)
