Is it the difference in DAC more important to the sound.
In my 25YR experience, the 3 salient things are cost, features, and reliability. The rest are mainly marketing and myth.
If features (Audyssey Dynamic EQ or something else) is not a factor, then it comes down to cost and reliability.
As already mentioned, especially by
@M Code in previous posts, Yamaha seems to have the advantage in terms of overall reliability. Some of us have had Denon AVRs that are still working after 9 years of use. I can't argue with statistics. But there is also the possibility that any Yamaha or Marantz could malfunction after 3 years also.
Nothing is for sure except for 2 things.
I think if Yamaha were to give in and adopt at least just Audyssey Dynamic EQ, I might become a fan of Yamaha. Maybe one day I may just try one out to see if Yamaha does have an answer/equivalent to Dynamic EQ.
However, cost vs reliability is another topic. If a $1,000 Denon AVR (like the X3000 series) can be bought on sale for $600 and it lasts me 10+ YR, I think that's a pretty good deal, considering how I absolutely love Dynamic EQ.
And if you are wondering if the Denon X3400 sounds as good as the Marantz and Yamaha AVRs you mentioned, you bet it does!
I just spent some time this last weekend comparing a Denon X3100 (which I paid $500) vs a $7,500 Denon AVP-A1HDCI Pre-pro. And I think the X3100 sounds just as good, which is probably a shocking statement.