mmm, mother of toilet seat
(for those that don't know, that is an official designation and is not a term of derision).
Roger Sadowsky claims that the fingerboard material is probably the most important wood in terms of affecting tone. If you run the same type of round wounds on both basses you should get an idea of which you might prefer (some people like both or don't care) as the electronics are similar. I'm decidedly not a maple fingerboard guy, but I'm also not a Jazz Bass kind of guy either. I'm a bit of an outlier on that. For whatever reason I am drawn more to the P-bass body shape.
Do you have flats on the black one? Seems like flats on that and rounds on the natural would be a good 1-2 punch.