I just recently bought a new bass, you know how some guys like to stay faithful to one brand? Well that was me for a very long time.
So... this new bass I bought is a different brand, with a different neck, and, most importantly--and I have now just discovered how important this is--different fretwire.
For the last few weeks, I've been fiddling around with the setup, and was going crazy over the fact that the action didn't feel the same as on my usual favoured brand of instrument. It seemed much higher than what I was accustomed to, the strings were about as playable as the cables on a suspension bridge. When I set up a bass I judge the action by measuring the distance between the top of the fret and bottom of string, like most people...
So I sighted the neck, the relief was minimal the way I like it. I even loosened the neck bolts and retightened them in different ways to see if I could affect the neck angle. But for some reason I had it in my head that the action should always be based on the recommended Fender specs and should never deviate from this. WRONG
I then had the epifany that this wasn't a Fender, and then I noticed the obvious: the frets were huge, jumbo frets to be exact. So with that I set the action lower to bring the strings closer to the fingerboard. Then I also loosened the truss rod which had been tightened in a vain attempt at making the relief dead straight. And it worked. Instantly the neck was transformed in became sleeker, playable, and way more comfortable in my hands. My fingers let out a sigh of relief and everything is just spiffy.
My revelation: different basses need different setups 
