Hi Gordon, I own Canon EF-S 15-85mm and very impressed by the image quality it produces. However it doesn't satisfy me when shooting at a low-light situation, now I'm thinking of returning he lens and get the Sigma 17-70mm f/2.8, will the image quality be on par with 15-85mm?
I like the expression of the guy at 10:20 when he was being asked in cantonese. lol....