For some folks, it's a no brainer. For some of us, it occupies enough of the brain that we start thinking on stage. That's a horrible thing.
I had a medium scale for a while. I have huge hands. I could play it, but when I wanted to play in on a gig, I would practice with it the week before, so I was relatively automatic - I don't like to have to look at the instrument much during a gig if at all possible. if I tried to switch during a performance, I'd end up staring at the neck to avoid small errors, which would kill the vibe.
I donated that bass. I also realized from that experience that I should pick one scale for both 5's and 4's. I'm a 34 all the time, regardless of the number of strings, or the presence or absense of frets. I think the biggest dividend that that pays is when I play fretless, I'm much more accurate because I'm always going for the same place.