Mickey MTZs are great. When I DD'd my rig, I ran the 35" MTZs to work, school, hunting, log roads, off-roading; everything. They did it all. I sold them with around 20k miles on them and they still had a ton of tread left. I've run 3 sets of BFG ATs in my life, all pre-new design. They were a great tire for the first 50% of the tread life (which seems to go quick). Then they kinda suck. I can't speak for the new AT design though. Those are supposed to have better tread wear.
Now I run Pitbull Rocker Radials and I love them. They're a great tire for all around driving. I don't expect to see 50k miles out of them. But if you're looking for a 50k+ tire, you should look at Michelins. Lets face it, 50k miles on some Toyos or Nittos, or whatever, is going to leave you wanting to buy new tires again so that you have decent tread. I've run the Toyo Open Country AT2s, and wasn't impressed, for the money that they cost. They're noticeably heavier too.
My advice,... buy a tire that suits the needs of the rig 90% of the time, and then add a traction device in the rear axle.