Yes, I've figured out that the "new" has "OS" and the ability to plug in and tune the AF profile. I've also seen that the "old" is about a grand cheaper, but availability is poor now depending on brand (B&H has Nikon but not Canon and Amazon has Canon but not Nikon).
What has me spooked is that Lens Rentals says this the lens that spend the most time at Sigma for repairs.
p.s. Thanks for the link to the review. I've read several, but this one seems to be the most comprehensive.
Last edited by ChrisF; 09/26/13.
