As far as I can tell, that's the beauty of the SI&I system, is how easy it makes it to switch the bindings, having almost the system you have, but the ability to switch at a moment notice and not need to plan?
Definatlely the system I'm going for as soon as they release it. I've skied on almost every other option except mfd, and all feel like compromises going neither up nor down extremely well. (excepting dynafit which is highly directional).