They're one of the best entry-level sets I've heard. I've been running an older pair in my wagon for about a year and a half now and they do well on all types of music. Midbass is lacking, but my doors are not sealed particularly well since I don't want to blow a lot of money on a car worth $800.
I'm running approximately 120 wRMS per side, and they don't break up even at max volume. Tweeters are slightly harsh at high volumes, though. The midrange sounds great, though. If you like guitar rifts, and loud, clear vocals, you'll love these speakers.
All in all, they're a great set for the price.