This may not help or answer your question, but try www.pixel-peeper.com and search on the camera lens and the body to compare.


I was in the market for the Canon version, and I have been swayed to the Sigma 70-200 by the retailers, but decided with the Canon.


The only concern is that the Sigma does not have the OS and I'm a little concerned about the quality control, but you can get that with any company including Canon.


Hope this helps and good luck.