Thanks for your thoughts and I agree. Being so new, there just isn't anything out there regarding testing the X4800h. Would you think it superior to the Cinema 50? Why or why not.
It is the Denon equivalent (features and specs) to the Marantz Cinema 40 so yes I think it is superior to the Cinema 50, only in the same way I think the Cinema 40 is to the Cinema 50. The Marantz models cost a lot more for reasons I mentioned before. Higher list price does not equal superiority, in fact, could (if depends) often be considered inferiority, that is, poorer value.
Have you watched the two videos I linked in post#3? That should give you much more specifics than the zkelectronics one that is only useful for a quick comparison.
Again, as HD alluded to, it is a matter of difference in the features, sound quality between all such AVRs should be the same, based on specs and the parts/circuitry described in those two videos.
Personally, I would never (almost) consider the Cinema 50 and the Denon equivalent X3800H) because I like the two line info display on their bigger brothers, the extra HDMI input, 2 more trigger outputs, and the larger power supply. The other differences such as the monolithic power amp design, AL32, DDSC are good on paper but unlikely to result in audio quality improvements.
It is hard to justify the extra dollars for the X4800H, Cinema 40 and even the Cinema 50 over the X3800H especially the money you can save by going with the X3800H can be used to cover the eventual cost of the Dirac Live DLBC that will almost certainly result in clearly audible benefits to those who don't want to spend too much time on tweaking Audyssey with the Editor App.
Obviously, if one considers value as most important, the X3800H is the best deal there is at the moment (among D+M's), but for reasons mentioned above, the X4800H is the best happy media for me, if I need an AVR. If you look at bench measurements, even the Denon AVR-X3700H performed better than any Marantz models including the AV7705/7706, only the SR8015 performed as good. The Cinema series appeared to have done something to improve their expected bench test performance so I would bet the Cinema 40 and 50 can match that of the Denon AVR-X3800H and X4800H, time will time when ASR starts to measure at least one Cimema series model.
By the way, I don't know if this has been mentioned before, if you are going to use external amp, the Onkyo RZ50 may be a very good alternative.
Disclosure: I have used both Denon and Marantz AV products, not long ago I still have 5 Marantz preamp/proc, preamp, power amp, now down to three. I have both D+M products in general.