With the rare multi-back and masks you can shoot 6X9, 6X6 and 6X4.5, The universal has a slide switch to move from 100 to 150 and 250, but needs a finder for wide angles. I have never used instant film or backs. The only thing I'm not a fan of that is that the shutters needs to be manually cocked. Both the Press and Universal are pro level rugged cameras, take a lot of abuse. In the 70s and 80 a lot of wedding photographers used them. Other option is the Konica Omega Rapid system. It was used by the Air Force, has excellent lens, only 3, a wide, normal and short tele, uses 6X7 backs. It was called the rapid because the film is advanced with a push pull arm, that cockes the shutter.
I used the Konica Rapid while in the Air Force, but decided on the Universal for the wide lens. The one lens I don't have is the 250, don't ever recall saying I wish I had one. The lens are found in chrome and newer all black models, folks say the all black lens are shaper. Although heavy with the grip I can hand hold my Universal and shoot as low as a 1/60th.