Kind of a mixed bag. The Gym had 1/2 of the lights off due to an electrical issue. Because of that I actually wound up using my 50 art at 1.4 quite a bit. Looking back through my images there wasn't a lot of really stellar shots with the 85 but I don't blame that on the lens.
I found the Tamron fast focusing with VC off. It just works. With VC on there is a little hesitation but it never took a way out of focus shot because of it. It just adds a small hesitation to the shutter. It does however, seem to improve my hit rate. This hesitation seems to improve the focus once the shutter is released.