Righto Brad... I have changed action many times and ther are things I like about it low like the growl, tapping is easier, and slapping is easier. So for me I like it low for the flashy special stuff.
(Victor Wooten, Marcus Miller, Manring etc..) or growly like Zender and Jaco.
But then there is that other side of me that loves punch and absololutely no finger noise when playing by the neck with a medium touch. So I try to keep it high or medium. It just seems like I get way less left and right hand noise with it a bit higher action. My drummers always notice a big difference in the punch of the notes.
I guess if I had a ton of basses I'd keep some low and some high. I am sure my F's action is a sin to most here on TB.
So the real diff to me is TONE and FEEL which varies from cat to cat.