I don't understad why goodyear decided to change to the mt/r with kevlar. I had 2 sets of 35s and 1 set of 37s of the old style mt/rs with the dura puncture (whatever) side wall and never had an issue with any of them. Some of the other guys I wheeled with ran KM1s and were tearing side walls up right an left. Downside to the older mt/rs was that you had to heat them up to get them to stick on slick rock, which kind of happened anyway when wheeling in Moab (circa 2005 before the sticky compound boom).
I agree with Nick regarding the pit bulls. Between that, and the fact that most of their sizes come in only "super wide," lead me to never running a set.
One tire folks are leaving out of the equation here is maxxis. Radial treps are pretty tough and so are non sticky creepys (which I wouldn't run on a rig that is a DD unless you only wanted to get 10k miles out of them).