I have a set of Pro-Comp extreme Mud terrains on my tacoma right now (the 35x12.5x15 variety) and I would put them as an OK tire. I've always been a BFG guy, but I liked the look and the toughness of the tire so I tried it out. They do very well in the rocks and snow and are pretty quiet on the street. I've had mixed result in the mud, but it's not a great mud tire (despite the name). My biggest problem is driving around in the rain. They are downright scary! It really doesn't take much for them to loose grip and this is the biggest reason I won't be purchasing them again. As far as wear, I've only had them for around 10K miles so I can't say too much about that other than they seem to be wearing at a normal rate. Hope this helps!
-Adam