I can verify that the Arcam also has the same ESS9026 PRO DACs and compared to the NAD DAC, it is disappointing. The Arcam isn't a terrible sound. I'd put it above most brands but the Arcam AVR21 is 4700 and it's not worth that. It also has too many drawbacks. I sold my NAD T778 and after buying the Arcam after having the Yamaha, I'm going to buy the NAD T778 again. I know I'm going down in features. 8K to 4K. But the user experience, especially for music, is so much better on the NAD. I have a large two channel external Emotiva amp and I bumped up the gain of the fronts on the NAD. Bumping up the fronts made it possible for the music to have more detail without having to turn it up as much. Then of course when you turn it up you'll be in heaven. If you don't have good audio sound from your NAD then you need to do some fine tuning. The NAD is the only receiver that I can actually hear the breath of a singer as they inhale and exhale. I did leave out Rotel but they only have one model and you might not like it. The Rotel sounds great as well.
We have slightly different opinions obviously, as I believe (based on experience and knowledge of many lab test reports) that like quality amps, avrs at the level of the T778, Arcam, Marantz, Denon, Yamaha, Sony's all sound may be subtly different but not distinguishable in most use conditions except when DSPs are used, such as different sound modes, room correction/equalization etc. So for DSP use, that most people will do, it will be a tough choice because there isn't much, if any lab test results to go with. To me, I would just based my choice on marketing information (unwillingly) but will try hard to find supporting data, such as the type of DSP ICs used sound modes/formats available, and to some extent go with my own subjective measurements in demo rooms. Overall, I would say at the level of the T778, there is almost no point wasting time in second guessing its so called "sound quality", as speakers and room, aside from the recording quality of the contents, it much more important. If those are good, any of those you mentioned will sound great, and also, that's regardless of whether TI, AKM, or ESS DAC ICs are used, as long as they are at the near flagship level, such as ES9026Pro and 9018 that are about 2 to 3 notches down from ESS's flagships.