the hardrock of this year shares rims with the p.1, p.2 and p.2 cromo, so it will be able to take abuse. plus, the hardrock is a much more durable, beefier frame. my friend has a hardrock sport but he likes xc... so he has to work a little harder than me. i have a rockhopper and i'm getting into a little djing, but not before getting a stronger wheelset. wheelies and stoppies can be done with either bike, although a rockhopper is lighter and therefore easier to hop.
still, you'll be better off with a hardrock - more relaxed geometry, and more durable. can't go wrong.