The 75B is, in effect, a new pre-B. It doesn't have a firing pin block, and that can give you a better trigger, when tuned (if it needs tuning.) In addition to the adjustable sights (which are so - so sights), it has an extended mag release, a trigger that can be adjusted for over-travel, and ambidextrous safeties.
(As I understand it, the adjustable sights were installed to allow the gun to meet the strange U.S. Government import restrictions. The lack of a firing pin block lost it points, while the adjustable sights gained it points... a sort of wash. It's all about getting the right number of points for it to be OK for import.)
Except for the firing pin block, it's basically an ambidextrous 75B with a couple of minor refinements.
I have one in satin nickel, which I consider CZ's best finish. (I'd consider the same gun in matte stainless if they ever make one...)
I think (but am not sure) that the larger, easier-to-use safety levers from the SA guns can be installed on the 85 Combat... and if you think you'll do SA much, that would be a nice addition. (You can also convert it to SA only, and install the two-way adjustable trigger, which is also adjustable for take-up.)
If you can find one for a reasonable price, the Kadet Kit (a .22 upper) can be a real tack driver when installed on the Combat (or on any 75-series frame.)
I've had a LOT of CZs over the years, and the 85 Combat is the only CZ I've kept. (Mine was the second one I bought...)