I wonder what the benefit of that back is. Ok - there are more film types available than 5x7 sheet film. But you can crop a lot of 5x7 sheet film before a $1100 back pays off. Or is it about converting a precision-gun into a machine-gun? Do you really go out shooting 6x17? And wouldn't you choose a GX 617, Technorama or Gilde in this case? Isn't panoramic format rather situation dependent? Will that back really help making a decision, how many film holders to carry with or leave at home? You will most likely end up with a heavier backpack.