From a couple of reviews I've read lately, the new generation trials tires might just be perfect for those rocky conditions. Unfortunately, tires are too big of a PITA for me to ever really experiment with different brands or types until I absolutely have to change one. So I have no experience with them.
I can tell you that a Sakura rear tire I had lasted forever, no matter what I did to it. Unfortunately, it pretty much sucked in any type of dirt, which completely defeated the purpose of being a dirt bike tire.