I went to see a Victor Wooten bass clinic and he was asked about his basses. He said he would always use his 4 string bass at clinics because he's most comfortable doing the "show off" stuff on a 4, but he uses 5, 6 and fretless on other gigs. Unsurprisingly he'll use what ever is appropriate for the gig.
Ian King posted a video on BC of him playing on Hamilton. He's using electric, bass, double bass and bass keyboards.
The "best pro players" don't seem to have the hang-ups that so many semi pro players do.