@soaringturkeys- yes the Canon 70-200 f/2.8 IS L version II was my first choice but way out of my price range. The Sigma was several hundred less. It does seem to perform quite well, I’ve been able to get some great sharpness with it, I’m just the problem at times I think. I’ve tried working with that focal length factor to keep my shutter speed up high enough, but I know it’s not something I think about all the time.
@Cameraclicker – Yeah all the lenses I invest in now are built for full frame (and also work on crop sensor) I am just keeping the two kit lenses I got with my Rebel for my non-professional stuff now like out and about /vacations, etc. Since they’re light and I don’t have to worry about damage. Also, my Sigma lens does have the two options. I usually keep it on OS-1 since I don’t do a lot of panning/moving shots when I use it.