My preference for comfort is usually 32", the 74 Hagstrom I picked up has this scale and a nice slim, sturdy neck. I find I can get around on that scale length better than most 34" s.
I played Peter Malinoski's 5 string Saga bass (still for sale on his website, shockingly) which is a 32" and the B string was absolutely rock solid. I even tuned it down to G and it never got unplayable or unlistenable.
Anything below 32" I prefer to have flats (for electric bass). I put high tension flats on a mustang with a darkstar pickup in it way back when and it was my go to hip-hop, dance bass.
And I played a Carl Thompson 5er with a 38" scale. It was comfortable and well balanced, still a bit of a stretch for the lower registers,but my god did it sound absolutely incredible. "Piano like" doesn't even begin to describe. 'You can go and have a bite, you'll still be hearing that one!'