He didn't say the DAC sucks, just ADC. In terms of specs on paper, and in relative term, the DAC chips suck too. 93 dB vs 107 dB SINAD is significant, again, agreed that it is likely not an audible issue in most (>95%?) real world use cases.A bit of an exaggeration saying the post fire DAC's suck.
Yes they measure a little poorer in the later Denon implementations but if any of that is audible is highly debatable.