Interesting question. I play four strings, exclusively, but I change basses depending on what I want to accomplish. Is there a difference between a Precision and a Jazz? Of course. But even more would be my Ps have flats and my Js
have rounds. How about a fretless? Absolutley needed for some works. Where I am playing will effect the quality/value of the basses I take, but in a nice place, it is all about the music we will play.
Honestly, I have 23 basses, all four string except for one 8 (octave) and they all sound different and play different, but I only have six go to basses, all Fenders but one. Precision, Jazz, Jazz fretless, Mustang (vintage), Performer, Kingman and the Washburn 8. (Byrds anyone?) All have their uses, some limited.
I will be interested to see where your thread leads.
Fender collection includes Precision,Jazz, Coronado II,Mustang,Tele,Musicmaster,Bullet,Katana,Performe r,DR4,Factor,JP90,Prodigy,Prophecy I,Urge,Urge II, Kingman. Have a couple non Fenders too.