Personally, I won't own another set of pro comp tires.. This story is why... This is my experience only, and my experience seems to be rare, but it was enough to keep me away from pro comp tires, and 4 wheel parts.
I bought some Pro Comp XAT's (that have a 40k mile treadlife warranty) from a reputable vendor here (4 wheel customs). Shortly after I bought them, I had a tread block separate from the carcass of the tire. I might have had about 2000 miles on them when this happened. I took them to a local tire shop, had them patch the tire from the inside, and then I went to 4wp, the closest place that would supposedly "warranty" the tire. They told me that since I had the tire repaired on my own, that they wouldn't warranty it. I then asked if they would reimburse me the $20 I paid for the patch on the tire, since it was obviously a faulty tire that caused the issue. They blatantly told me no. So, I went home, with a "fixed" tire, that I paid for, that was plainly a molding issue, and not an offroading issue.
Fast forward to about 3 weeks ago. I noticed the tires were wearing really quickly, and almost down to the wear bars in the rear, and getting close in the front. At this point, I had about 20k miles on the tires, and have rotated them every 5k miles. I again, took them to 4 wheel parts in hopes that I'd be able to at least get the tires pro-rated, and make the next set cheaper, since they only really lasted half the miles that they are warranted for. Again, I was given the run around. They asked me where I lived. I told them that I lived up in the mountains, and that the truck saw winding mountain roads daily, but they should still not wear out this quickly. They have worn pretty evenly to this point. The "service advisor" point blank told me that mountain driving is not "normal driving circumstances" and that they would not warranty the tires, but would mount and balance a new set for me, for free, after I paid full retail for the tires. Needless to say, I walked out, after telling the guy that I'd never shop at a 4wp again. For anyone that lives in so cal, the Riverside 4wp is where all this happened. I am still running the tires, only because I am working on saving $$ for tires, because at $200 + per tire, they aren't cheap. Still trying to decide on my next set....
Just my experience.