The Toyos tread design looks like is was patterned off the MT/R with a lean to the traditional MT tread design. Just guessing here...the MT/R is probably a better rock tire, and the Toyo MT is probably a better mud tire.
Any reason TRXUS MT's are not on your list? I went with TRXUS because of the onroad snow capability, which is unbelievable, without sacrificing a quiet ride or all the good offroad capability.
I seriously considered MT/R's, but I don't think I'll ever find the limits in an 80 where the extra rock capability is discernible, and I've always had doubts about the MT/R in severe winter conditions (I seem to have a high probability for unintended winter misadventures with my family, so I plan for this