"But if you can't trust your ears, what can you trust"?
How do you adjust all the parameters of a TT and listen at the same time? Let's take the easiest adjustment, which isn't too easy on my TT bacause of the arm; but tracking force for example. Do you try it at 1 gram, sit down and listen, then 1.5, followed by 2 grams, and what are you listening to; what kind of music? Which music sounds best at what tracking force? What do the specs that came with the cartridge call for? As you stated, you can't even trust the accuracy of most gauges, so you're really using "Kentucky windage" at best, according to you; but you stop when and where it sounds best. I must admit, all of that "sounds" real good.