I had a single 12" and it rocked. The only thing I didn't like about it was that when my ex-gf was w/ me, I could never have the volume about 10 or she would sit with her hands over here ears the whole ride.
It does really all depend on getting everything set up properly for the brand you go with. I like you listen to everything, from rap to rock to country to anything else. I never had any complaints about how it sounded while playing anything.