I use my ears, 100%.
Every once in a while, I get the bug to change some settings, adjust some parameters, that sort of thing...
Invariably, I tune it back to where it was (or very, very close, anyway).
That leads me to believe I’m pretty much at the limits of my equipment. I’m OK with that.
I have never, ever had anyone who has listened to my system not leave smiling.
I have no idea how it measures. Sure sounds good, though. 😎