Originally posted by StreetShooter
I'm a bit late to this thread, but I must respectfully disagree with Ckiang about the Sigma 24-70 f2.8 EX. It's very sharp for me. The extra 4 mm is very important if you're a DSLR user. The 82mm filter is expensive, yes (paid $77 for my multicoated slim one), but that's the price you pay for the extra wideness. Heftiness of a lens has never been a problem for me so far (but then I don't have a 50-500...).
Maybe they got high sample variation. I tried it when Red Dawn first got it, tested it on the D30, both of us don't like it. Returned in less than a week. ;p
Regards
CK