I buy all my lenses from B&H.
Where ever you buy from you will enjoy the 70-200 lens
Regards
Bodies : Canon 450D, Canon 7D
Lenses : Canon 15-85 f3.5-5.6 IS USM, Canon 100mm F2.8 Makro USM, Canon 24-70 L F2.8 USM, Canon 70-200 L F4, Canon 100-400 L F4.5-5.6L IS USM
Editing : Photoshop CS5
My daughter has bought a couple of lenses from DD Photographics without any problems. I bought the Sigma 70-200 2.8 when I was in Hong Kong (not the new IS version) and I had nothing but trouble with the AF on a Canon 400D and 50D. After many visits (around 12) to C.R. Kennedy in Sydney and two returns to Sigma in Japan, it was finally replaced with a new one. I must say though that C.R. Kennedy were wonderful through it all. I decided to sell it and buy what I originally wanted but couldn't afford at the time - a Canon 70-200 2.8 L series (version 1).