Is Yamaha that much more superior than Denon as far as sound?
To me, they are equal in sound quality in Direct/Through mode (bypass Room EQ).
If you feel like you have to use Auto Room EQ, I think Audyssey is better than YPAO.
I switched from a Denon AVP-A1HDCI to a Yamaha CX-A5100. It was not because of sound quality.
I just have a feeling that Yamaha is more reliable. I can definitely say my Yamaha is more compatible than my Denon in terms of HDMI connection with my DirectTV receiver.
Time will tell if Yamaha is truly more reliable for me. But for now, if my mom or dad were to ask me for a recommendation, I would recommend Yamaha to them.