This may be a bit out of context. My view on the different methods of gain setting relates to psychoacoustics.
Wealthy audiophiles will spend thousands of dollars on speaker wire and signal cable. Whether or not the improvements exist is one thing. But if they BELIEVE that it sounds better, it is worth it to THEM.
If you believe using tones and a dmm will make things better, it will.
Audio is to subjective to be objective. For the most part.
