Sony 70-200 vs. Sigma @ f/2.8

Thinking of "downsizing" in lens cost.

Does the new Sigma 70-200 come close to the Sony @ F/2.8 and 200mm?
It looks like focus speed is great.

I have a Minolta 80-200 f/2.8 APO too, but sometime the screw drive jerks the lens (and is noisy) when focusing, and blurs the image.