I've only had a few minutes to review your excellent posting but one point struck me as I saw the size comparison pictures: A medium format Leica is only slightly larger than a Nikon D3x, D3 or other FX format cameras. The same was true back in the film days when Nikon went from a large F4 to a giant F5. Carrying around a Nikon F5 as a landscape shooter was sheer overkill, both feature wise and sizewise, hence my move to medium format, at the time a Contax 645. The same today as you show in your size comparison, the Leica S2 is not a whole lot bigger.