It is really such a shame that there is only one color film left in 5x7 format (Portra 160NC). It is my favorite of the large format sizes. It is almost twice as nice as 4x5, and has an aspect ratio that I prefer by leaps and bounds over the "ideal" format of 4x5, 8x10, 6x7cm, etc. Also, I agree with others who have said that 5x7 is noticeably more convenient than 8x10 as far as the bulk of your kit goes. If I was going to divide images on an 8x10, I would do it vertically (5x8) rather than horizontally (4x10).