A few people use the bronica.. but as it was a fairly unreliable camera to begin with, and now quite venerable, there is not much demand.
my first medium format camera was a bronica S. I really liked it and I was very pleased with the quality of the images.
However it locked up very badly. I replaced it with an S2 which sometimes worked, but I much prefered the rack-and pinion focussing of the original S.
I sold it a few years back. While I miss shooting 6x6, I dont plan on going back to the Bronica S system simply for reliability/repair issues.