Engineering wunderkind Bob Carver was not impressed. That's enough for me. He says only a bat might hear a slight difference now. That MQA was changed from its demonstration algorithm when it first rolled out to how it is being currently implemented.
More damning to me is that once the purveyors of it convinced some labels of its value, they took the licensing money and ran off into the sunset.
Bob's engineering white paper is at this URL here: