After seeing the lens on display at Adorama in NYC and how compact it was, I searched the net for a review. I guess the lens is too new, I could not find anything, so I decided to test it against the Canon 24-70L and the Nikon 24-70, wide open (2.8) at 24mm and 70mm on the Canon 5Dmk2. I forgot to mention in my review that the Nikon zoom ring feels pretty good, the focusing ring not so, too loose for my taste, better then the Canon but not as good as the Sigma. AF feels pretty much identical on the Canon body compared to the L lens. Check out my mini review if you are in the market for a standard zoom lens and are wondering about the Sigma.