They do have a point - can we (humans with decent hearing) tell the difference between pre-amp SINAD 87 (X3800H) and 97 (X3700H) when not using quality headphones? When using the built-in amps the SINAD at 5W is very comparable (85 vs 88 for X3700H). This evasive behavior does tell clearly that the company used an inferior part for some reason (fire at AKM factory) but I am not sure that matters outside of measurements.
In my opinion, the comparison between Cinema 50 (many in the forum have it) and X4800H (preorders starting to show up) is fair because they are priced similarly and have some
audio enhancements in the specs that Cinema 60 or X3800H doesn't (Cinema 60 is definitely the weakest of them all). In terms of specs, I don't see X4800 standing out over Cinema 50 in quality, just has slightly higher output / extra HDMI / zone.
Also from OP's review, Cinema 50 seems to be better than X3800H with SINAD at 5W (89dB for RCA) being slightly higher than X3700H though I'd wait for Amir's review before arriving at a conclusion just to make sure it's the same bench used for measurements and also, the HDMI input matters more to me than optical / RCA.
If it doesn't void the warranty, I could take the lid off of my Cinema 50 and take a picture. Assuming the DAC isn't hidden, of course.