I don't know what there is to "hear" in this context. Measurements conclusively show that there is no sonic difference as far as fidelity. If I sold you a $5000 filter that I claim would double your gas mileage in your car if you ran your fuel through it, but lab tests showed this to not hold water whatsoever, you would only want to hear from people who have used it??? That people read and understand the report means nothing? They should stay quiet because they have not experienced such?
That is wrong, correct? The whole purpose of creating objective data is that it doesn't matter who is looking at it. Me with equipment at hand or someone not. We are both looking at the same data.
And the whole purpose of audio equipment is to listen to music. If the data have no relevance to that purpose what is the point? Using your fuel filter analogy, you never drove the car. The numbers are relevant only in the context of their actual use. If you look at the window sticker of a new car you will see the EPA fuel economy measures accompanied by "Actual results will vary for many reasons, including driving conditions and how you drive and maintain your vehicle."
You write "Measurements conclusively show that there is no sonic difference as far as fidelity." The first definition of sonic in the Merriam-Webster dictionary is "Of or relating to audible sound". Where did the audible come in?
I don't own a PowerPlant. Simply because I don't have a need for it. If, however, my system did have noise problems that I couldn't resolve with less expensive methods, would I try one? Perhaps. There is little subjective about putting your ear up against a speaker, hearing noise, and then making a change and not hearing the noise.