The things that concern me are that Yamaha appears to have slipped in the audio quality area in the last few years. Are these "good enough"? I've never owned a Yamaha component, but I've always looked at them.
My TV is a panny PZ700 and it does a great job with SD stuff like the directivo. The other devices I have connected are upconverting DVD, HDA2 and directivo HD DVR HD21-700 and HD tivo HR10-250. There are plans for a BD50 when they come out.
Well Yamaha sounds good. I would say it does not carry as much current as the old models, and is missing a little low end, but still sounds great with my speakers. The key is the type of speakers you have.
I have Energy speakers and I do not like the way they sound with Denon. Very muddy with a mid range boost but great bass.
The Yamaha's sound more open and clear, yet not tinny like a Sony ES and what I hear of Onkyo is that is sounds like Sony, but have never spent time with Onkyo.
Below is an overview of what I think the receivers sound like.
Denon - Mid boost good base and current, not as open sounding. Sounds great cranked, and with lower end speakers, especially Polk or Klipsch.
Yamaha - More open and better sound field and depth. More natural to me with less bass, but vocals sounds great.
Sony ES - Sound similar to Yamaha's but at more high end and sound less natural. More Tinny sounding and can strain the ears.