Why should we raised the price point for people over headroom that really isn't necessary for the general public?
Manufacturers never add quality to their product that is not visible to the general public, so no worries...
But every manufacturer has a different level of commitment towards quality, and all I am saying is that ACD test results tend to be an indication of that.
How realistic would it be to simply upgrade your amplifier's power supply?
I think for a person of the OPs expertise it would be an option work exploring.
Out of reach for most people, but not complicated for a technician. And cheap, there's a lot of broken monster amps on eBay with great power supplies (must be of same voltage or slightly less). However as was said before, the extra current capacity, if used fully must be handled by the amplifier's output stage, otherwise poooof.
As a HK owner I still much prefer the Denon approach.
I think you are saying that for the same ACD power, you would prefer the amp that has the higher stereo power. The advantages are that it also cost less to produce, and is lighter when you need to rearrange your setup.