I liked the MT/R LOTS better on the road for my XJ. I ran 32" & 35" MT/Rs and loved them for what they were. In between, I ran 33" SSRs and thought they were OK, but was glad to get back to the street manners of the Goodyear.
I thought the MT/R also held a line offroad a little better than the SSR. For example, Rockpile in Pritchett. The MT/R would stay 'straight' more as you were climbing while the SSR would 'wander' a lot more (to point that I'd have to back down and start over more often).
I think they both wear pretty similarly, but I'd have to give the wear nod to the MT/R. You'll need to keep them both balanced and rotated to get good life out of them. Neither are a bad choice, I just think the MT/R is better.