Quote Originally Posted by fabian628 View Post
Depends on whether the IS compromises the lens in other ways but having 4 stop IS is useful. Shooting indoors at 4 stops lower iso on stationary targets is pretty good imo. IS makes taking the picture easier / more success rate, I dont see why a professional would not want such a feature.
Obviously canon knows how to make lenses so it is a little interesting why they left it out.
It depends on what you do. Wedding guys would probably appreciate IS as they are often shooting in low light. If you shoot on a tripod, as I do for 95% of my work, IS is useless.

Another thing to consider about IS is that it doesn't slow your moving subject during your 1/4 second exposure. If you shoot people, as long as they are actually alive, they will be moving about! IS is nice on longer lenses, where camera shake is a bigger problem at even medium shutter speeds.

JJ