I just learned that on Friday and Saturday of this week during Photoplusexpo in NYC, Calumet will have reps from Mamiya, Sinar, Phase, H'blad, and Leaf in their 22nd street store. They will have a model or two and a still life set up and will allow those of us who drop by, the opportunity to test out the equipment. This sounds like a great opportunity to test the backs against one another.
I am not affiliated with Calumet, but am posting this because many of us have been asking for an opportunity to do just such a comparison.
regards.