Not sure where you're getting this info about the P5, Eric. Are you basing it on your own experience with the P5?
I've got the P7 myself and was debating the P5 when I found a used P7. I did much research on the P5 and never heard or read anything critical of it for the price. The Parasound Classic 2100 is the basic performer here, not the P5. The 2100 is again quite nice sounding for the price, and the P5 is a good step up from that. The P7, though quite good, employs op amps and not discrete circuits.
I've got the P7 myself and was debating the P5 when I found a used P7. I did much research on the P5 and never heard or read anything critical of it for the price. The Parasound Classic 2100 is the basic performer here, not the P5. The 2100 is again quite nice sounding for the price, and the P5 is a good step up from that. The P7, though quite good, employs op amps and not discrete circuits.