This may sound strange but I bought my second Sigma 70-200EX. I've had the old non DG/non macro version for a few years but I recently have been doing some shooting that not only required a fast zoom in that range but it had to have HSM/SDM.
My wife has been training our dog in agility and he's finally just starting to run trials, I made the mistake at a practice of not using a silent lens and as soon as the "swirl" of the lens happened the dog looked up, saw me and ran to me.
So I needed a fast lens (especially for the indoor stuff) in that zoom range with a silent motor, which meant the Sigma was the only choice.
So I got the lens tonight and of course the 1st thing I did was check for focus accuracy, sharpness ect. As some reports have said it is softer wide open @200mm then the old non DG version. It also front focused at 200mm slightly which seems to have been resolved by a focus adjustment (found a good compromise that didn't seem to affect other focal lengths). That being said after some real world testing it could be going back if the focus is off.
The other thing that makes me not as excited about the lens is that I've been shooting with my DA*300 almost exclusively since I got it and it really does blow the Sigma away. That d%*m incredible IQ of the DA*300 is ruining perfectly good LBA for other lenses. I really wish Pentax had that range in a DA* f/2.8 lens.
I have to say that this is the only time I've ever thought about running a dual system and picking up a used 40d and 70-200 USM (which is supposed to be superior to the Sigma)
Oh well, just thought I'd share as everyone here can relate
I'll post some examples tomorrow.
Thanks
John