I was considering picking up a Sig P210 or a S&W 952-2. Performance wise, I believe they are the same. I decided on the 952 because the availabilty of mags and other accessories. Now my problem is, should I get the 5 inch or the longslide 6 inch?

IMHO if you are going to use it for games like Steel Challenge, Steel plates, and the like go for the long slide. If you are going to shoot bullseye and plink go for the 5".

The 5" for sure. First of all there aren't a lot out there for sale and I don't think I have ever seen a 6 incher for sale. Second, the 5" is so accurate I can't imagine I could shoot any better with the 6". I guess if you were always shooting at 25+ yards it might help but I can't see that far anyway.

How does it compare to the Sig P210.