I have had the original BFG mud terrains and the Cooper STT tires on a couple of different vehicles. My first set of BFGs were used with about 60% tread, 31x10.5x15 and I ran them on an 87 cherokee with 3.5 inches of lift. These tires were horrible in the winter and any wet conditions. They were good in the mud and in the sand. Then I bought a set of STT for the same vehicle and same size. These tires were ammazing in all condiditions. I had the Jeep at Michigan Tech so I can say they worked well in snow and wet conditions. I sold the vehicle so I have no idea on millage on the tires.
Then I bought a set of 285 70 R17 load range D for my 96 chevy half ton. These were ammazing in all conditions again from snow and ice to sand or mud. I rotated these tires every 7,000 miles when I changed the oil. I ran these tires for 55,000 miles and they were down to the point that I wanted to replace them. You may have been able to stretch these out another 5,000 miles at best. I also had this vehicle at Michigan Tech and would drive 1200 miles round trip to come homw for breaks. So these tires got a good mix of highway and non highway use.
From my personal experience I would recomend the STTs to anyone. The only thing I saw happen to a friend is that he worn a set out in 30,000 miles but that was becasue he put load range D tires on a 1 ton diesel and used the truck for towing a large enclosed trailer for snowcross.