Here the Sigma Macro at both 300mm and 200mm is compared at f/13 optimum versus the old Sigma APO Macro Super @300mm at the same aperture, the Nikon 80-200 @200mm f/8, and the Nikon 300 2.8 plus 32mm extension tube @300mm f/8.

The Sigma shot was taken just as a few raindrops fell....the old Sigma and the two Nikon lens shots were taken just a few minutes later, but enough rain had fallen to make the shot slightly different. Lighting did not change during this time, however.