I've been on 35" MTRs for 7 years with kind of a love/hate relationship. They're really not great on the road. Icy roads are a definite problem. They're pretty good in loose snow or even somewhat packed. I've never had problems with rain but standing water at highway speeds gets your attention. The stiff sidewalls make for a rough ride--even at 22 psi where I run them.
Off road they're really fun. Deep mud? check. Steep sandstone? check. Sand? check.
The tires have become impossible to balance over time. Shop just told me I had to replace them--even with a lot of tread left. I didn't replace them but I added 11 oz of airsoft pellets (0.25 gr each) to each tire. That really helped smooth out the ride. I got a nail in one tire at the corner near the sidewall. Shop told me I had to replace the tire as it would not be fixable. I put the tire back on and aired it up. That was several months ago and it doesn't lose air.
So, in my experience, the MTR is a great tire but I don't think I will be buying them again when the time comes. The on road performance has too many compromises for the way I'm using my TJR now. I'm not sure what I will be replacing them with.