Since I originally posted this, I bought the Knarly XC 6-Ply. I've gone on two rides with them and I love them so far. They grip like crazy and look pretty sick. I just ordered the front Klaws to go with them. I also read an article where they ran them in the Baja, or somewhere like that, and never punctured them. That's the reason I wanted 6-ply, since I ride some VERY rocky terrain. Anyway, thanks for all the replies guys, you helped me make a good decision. :beer: