Simga 70-200 f2.8s

Whoops! My bad. Wrong 1 and 2!

Anyway, as far as I know the differences were negligible, and perhaps a reason nobody cared enough to do a proper comparison.

I hesitated to post Bryan's review - as he's had nothing but horrible luck with Sigma lenses, but here it is for the version 2:

http://www.the-digital-picture.com/Reviews/Sigma-70-200mm-f-2.8-DG-HSM-II-Macro-Lens-Review.aspx

And his brief thoughts on #1, which was basically, sell it!

http://www.the-digital-picture.com/Reviews/Sigma-70-200mm-f-2.8-EX-DG-Macro-HSM-Lens-Review.aspx

His biggest problems with Sigmas has always been focus consistency.

Of course it looks pretty good on the ISO charts:

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=469&Camera=453&Sample=0&FLI=0&API=0&LensComp=0&CameraComp=0&SampleComp=0&FLIComp=0&APIComp=0

For the record, I have the 70-200 f2.8 OS and love it.