This may have been covered but did not find many of you use a roll film back on your LF camera? Crown/Speed Graphic, Busch Pressman, etc.
Was wondering because with prices at a low, I was considering adding another Mamyia 645 body for back-up or even parts, but then I have a Crown Graphic and it would seem like just adding roll film back would be nicer, giving a 6x7 or 6x9 negative.

Any thoughts, do you focus, basic workflow using a roll film back on LF camera.