Im running Polk db6500 6-1/2" component speaker system with Pioneer DEH-P6900UB. You will notice HUGE difference between stock speakers and stock head unit. I have it for 4 month so far and im really happy. Speakers produce great clear sound, highs and middles, sound really nice and plus 2 12` subs give all the bass i need. Im also planning on changing my rear ones and im probly will go with polk again to match up.
just my 2 cents