Bassman,
It has been my experience that only when playing at very loud volumes will a receiver make a difference. I have tried my Axioms (M80's) with 4 different amps, and only a Harman Kardon at a loud level sounded better and had more bass than the others. Otherwise, the sound is the same.
If you do not want to get your Pioneer fixed, and want to spend as little as possible, you can try looking at
www.ecost.com, or harman kardon's official website and pick up some factory refurb receiver. Ecost carries Denon, which is a very good brand, IMO. I also find Onkyo to be worth the money.
The Sherwood Newcastle's definitely look great. I may purchase their R-972 when released this fall.
