I use a 692 for sporting clay's. As for the difference between it and the black version I thing Shibby nailed it, it has a carbon rib and it's black, I'm not aware of any other differences.
As for differences between the 692 and 686/687, there are quite a few and worth the extra money for a target gun in my opinion, the only things that are the same are the trigger and ejector mechanisms and stocks. The 692 has a wider and heavier receiver than the 686 which puts it up into the lighter target gun weight (around 7.5 lbs) instead of a field weight gun such as the 686, this makes a difference at the end of a 200 or 300 round day and the extra weight is between your hands where it should be for balance. The other major difference is the 692 has Optima barrels which are over bored, use Optima HP chokes which are superior to Mobil chokes (686/687) and have 14 inch forcing cones compared to 3/4 inch on the Mobil barrels of the 686/687's. There is no question in my mind that these features make for a softer shooting gun which again makes a difference at the end of a long day shooting. The 692 also has the adjustable weight system that lets you fine tune the balance of the gun.
I have the B-fast comb on my 692 and it's a vast improvement over the older adjustable combs found on 682 Gold E's and the likes. I had 4 different Gold E's with adjustable combs and I never had any problems with them but lots of people did. The new B-fast system is more durable and I haven't heard of any issues with them.
