As one that A) spends more time than anyone at Chimney Rock and B) may unofficially have the fastest lap times there, I will say, there is no one tire that's better or worse. Last year I rode for Kenda and tried every tire they made, this year I ride for Bontrager and have every tire they make. I've ridden dozens of tires through the years, I'm a self-proclaimed tire-whore. You should see my collection. The tread pattern doesn't make a difference, just find something you like that either looks cool on your bike or something that your friends won't make fun of you for, and then lower the pressure until it hooks up, you'll be fine, if not, blame me and then go buy another tire you think will make you turn faster in rocks
-Jim.