MT/Rs
craig, I didn't have the Coopers long enough to answer that question. Sounds like results may vary. Nathan can probably advise us all on how often to balance/rotate the Coopers.
Another thing, with the Coopers and with the MT/Rs...I don't run them on the road except to/from the trail. I have separate rims and tires and have stock 19" rims with Michelin Synchrones for the time I'm ON-road, which is about 90% of the time. I'm probably going to get 60,000 miles out of the Synchrones. ...which is good but not compared to the 100,000+ I got out of each set of Michelins I ran on my old Montero.
I have only been off-road in the MT/Rs once so far. They performed well, but it wasn't all that slimy of mud, more like hard-packed dirt that was wet. There were a few nasty spots (see attached) and the tires were flawless. Yes they are louder than the Coopers and don't handle as well on the road. I doubt they would wear as nicely...