For those who care Trinnov can maintain full resolution and sampling rate when processing all its various codecs and applying correction, whereas the vast majority of AVR/AVP units down-sample to 48 kS/s as soon as you engage room correction. It also tends to offer more decoders sooner than other processors (e.g. IMAX).
The number and length of the filters, along with the user's ability to program them, is greater in the Trinnov than any AVR and most if not all AVPs (all I know, but that is not "all"). And of course the ability to manage crossovers and target curves is greater than most other processors (Dirac Live comes closest IME).
Higher channel count than most AVR/AVPs is good for some of us -- I am using 15 of the 24 channels in my SDP-75.
There could be lots of reasons the Denon room was preferred, including speaker choice and setup, room interactions (SBIR, modes, etc.), different frequency response curves in the processors that favored user preference more on Denon than on Trinnov, etc.
For me, once performance reaches good enough such that distortion and noise is inaudible, then it is all about features and flexibility. I don't think any AVP/AVR tops the best stand-alone DACs' noise and distortion performance, for instance, but I question my ability to hear the difference going from say 100 dB to 120 dB SINAD vs. hearing the result of the Optimizer and fine-tuning the filters that leads to better sound compared to my previous Emotiva, Denon, Pioneer, Sony, and Yamaha AVRs. That said those AVR/AVPs spanned years so I certainly have not done 1:1 comparisons, though I have measurements for some showing how much better the Trinnov did.
At this point I expect the argument to fork into either (a) "but the measurements still suck compared to XYZ" and/or (b) "that just means your ears/speakers/system/whatever are not good enough to hear the difference".
Onwards - Don