Well, I have had very good luck with Yamaha, and feel they have usually been priced fairly.
Pioneer has produced some excellent valued receivers. I can't but help thinking Yamaha receivers may have a little better quality than Yamaha, based on anecdotal evidence. People have come to this forum complaining about somewhat new Pioneer receivers dying on them. Usually when people come to say their Yamaha receiver does not work, it's an old model.
I would not take any of this too seriously though, because I have no real data. The only "fact" is that Yamaha receivers have generally worked well for me, and all the ones I bought that I know about still work - only one needed service, and that was a stereo receiver, not an AVR.
(I have owned the 795a (still working far as I know,) the RX-V665 (still working in my bedroom setup,) the RX-V2700 (sold to a friend, still working I believe,) the RX-V3900 (sold,) and now the Z7 (my main receiver, works perfect.)