Very nice I've had experience with 6x9,6.5 Type R's. Best 100$ speakers out there. I used Alpine Type X' 5.25 and the sound quality was amazing but did not get loud like the Type R's did.
Make sure you buy the PDX from a reputable dealer. My brother had the 100.4 and 1000.1 and had issues with them both- The heat sinks are just to small and they heat up.