I just know what feels most comfortable to me....I used to have 36" scale/19mm spacing basses.....my little hands just didn't dig that.....and my playing has changed and the smaller basses just work for me best. I've got a Ristola 33" scale bass with 16.5mm spacing in the works. I'm very excited.
I've gone just the opposite route---I used to swear by 17mm spaced 5 and 6 strings. But now, my playing has changed (slapping a lot more, for one), and I'm finding myself most comfortable on wide spaced 5's. Funny how that works.
