i listen to a lot of punk, ska, and general rock stuff. i can say without hesitation that rock sounds excellent on ascends. i don't know how "hardcore ascendian" i would be considered, but i, too, was worried that my rock (a lot of it underground, small-budget recordings) would sound bad, but nearly all of it sounds great regardless of recording quality.
i actually have a couple CDs that i've always thought were recorded really bad, but they sound 10x better on the ascends. likewise, i have some great cds that seem to lose something. the first time i listened to nirvana's "nevermind" album, it didn't sound too hot. last time i gave it a spin it wasn't bad, so i don't know what the deal was with it the first time.
anyways, don't worry about your music sounding bad on the ascends!
CMT-340SE2 Mains & Center, CBM-170SE Surrounds, Rythmik F15, Emotiva XMC-1, Emotiva XPA-5