re: fps + leaf shutter in the S
Need I remind about this article? -
The New ALPA 12 FPS
Scroll down to where they are comparing a Copal leaf shutter to the ALPA 12 - "You will need a good monitor to look at these two images, particularly because things are not quite as clear with a JPEG, but if you look carefully at the edges of the numbers, at the fine textures and at the fine "pebble like" finish of the background in the license plate I trust you will agree that the image on the bottom is sharper and shows finer detail. (the FPS result)" The shutter used in the ALPA 12 is modified Mamiya unit.
I think any worries about shutter vibrations need to be put to rest with a simple objective test. It could be a current design limitation that requires the S to activate both shutters, but it's also no guarantee that even so, the damping might be good enough for it to not matter. If you had to pick any manufacturer that knew the most about soft shutters, it'd be Leica; for them to overlook something like that would be like hiring a model, but no hairdresser or makeup artist.