Jimmy
I have the 2.8 IS and I like it, you can probably live without 2.8 IS since I'm assuming you have lenses that would fill that hole. I know it doesn't answer your question since it is the more expensive lens but they are cousins in the same family so how different can they be. It focuses quickly on the EOS 1ds, I don’t know if the camera would make a difference on focus speed. Here is one of my most recent shots. 1/80 @ f2.8 153mm off camera flash, hand held. Now if I can only learn to see the light as masterfully as you do.
Ken
