I've been running them on my truck for a while. All around, they're a pretty good tire. Only downsides to them are they don't like to stay balanced and they're pretty loud.
Mine are on their way out. They've progressively gotten louder as they wear and I'm at about 40-45,000 miles on them. They don't like to stay balanced like he said. The tread started wearing terribly about 15,000miles ago and now they're riding like crap.
Maybe I coulda rotated them more often and that may have made it better, I know some have good luck but this is my experience.
Procomp xtreme all terrains FTW! Ive run 3 sets and have got 50k out of each before replacing them. Well, two sets..one got 30k on it, and had a sidewall break down so I bought a new set. Of course, I was dragging some heavy crap all the time.