If you're using it as a hand-held press camera, e.g., focusing via a rangefinder or even estimating the focus, you can keep a 120 film back attached and avoid the hassle of loading sheets and you have a much smaller kit to carry. 120 film is pretty convenient to use, compared to sheets. If on the other hand you're always using it like a field or view camera, e.g. on a tripod and focusing via the ground glass, then you may as well use the larger camera.
Originally Posted by edcculus