Steve, it seems to me that there's one difference between the Cambo stage and the P1 stage, namely that the Cambo version opted for a central knob in the middle to both move the left and right masks at the same time, while the other stages in the market allow one to move both mask slides more to the left or right in any asymmetrical fashion meaning one can move a negative holder around on the stage for say stitching - is my analysis correct?
I think they didn't think about the need to stitching in the Y dimension, but only about stitching in the X dimension, or sliding of a 120mm film holder with a strip of captures; one might want to do a quad stitch on an 8x10 for example so the Y dimension would also be useful, IMHO.
But I confess this is a niche use case as most will prefer to scan in one shot and the IQ5 240 will essentially be a Tango Drum scan res shot in one 1/15 of a second so nothing to complain really.
One other difference seems to me that you cannot fully mask out the top and bottom parts of the 8x10 glass negative holder on a 8x10 neg as it has a tiny bit of space at the bottom and top and the top and bottom masks are also the "rails" for the neg holder ... ?
This said, the Cambo film capture stage probably is by far the best deal out there and arguably a solid setup beats any Imacon or Flextight kit any day of the week in terms of speed and DR.
This comparison shows that an IQ4 smokes an X5.