After you have used any system for some time, whatever its logic may be, you will be able to use it without any metering as long as you stay in your neighborhood. West Virginia is mine now. It was once upon a time the rehearsal stage of a symphony orchestra. If I moved west of the Mississippi, my instincts would no doubt have to be revised. I would probably resort to BTZS to accomplish the revision.
As with some others, I don't see the point of arguing the supremacy of one system over the other. How was my grandfather, in his limited number of years which ended in 1905, able to get over 100 5X7 glass negatives that I can print now? I do see the need for presenting as many systems as are known so that one may make a choice. I gave private oboe lessons for a number of years, and found that different students responded better to one approach or another. The important thing about the oboe is what goes on inside the mouth, which I can't demonstrate very well while playing, so I must resort to different analogies for different students. Granted, some will still sound like a wounded duck, but that is because they don't have a tonal concept. Of course, we photographers each have a tonal concept, don't we?