For being in the DH set I find my disc brakes to be invaluable since it is nice to get woahed down at the end of the run.

As said the hardrock is designed to be more along the lines of the big hit hardtails, with the hardrock and when a rider on one is ready to step up to the next level of bike in the specialized bike line and stay with a hardtail, they usually go with the Pseries(P1,P2,P3,P3street)