I'm not sure if the Rhinocam will be of interest or not at this point. I have the Canon Tilt and Shift lenses, and, frankly, I find I mostly grab the lighter, faster M9 and 35 and stitch in Photoshop. For the very wide pans, I also find I like the cylindrical mode of stitching better than a rectilinear approach. So, it's an interesting approach and I see the benefits in the accuracy of perspective, etc., which would be much appreciated in the cityscapes I increasingly like to do.
Do you have the 50 Distagon (non-floating element) for the Hasselblad? If so, have you found it holds up well enough at infinity? (My Rollei SL66 50 was very weak at very close focus, but for the cityscapes I have in mind, that would not be an issue.)