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I did expand on the handling of SSS in this version, as well as ordinary diffuse and specular and other effects. Everything here is based on the principles of layered interactions. I start with a certain percentage of incoming energy available for specular interactions. As the energy is consumed by those in some areas, there is less to reach deeper for diffuse reactions, or SSS reactions. So by building the material response in layers, instead of just adding a bunch of independent effects together, I get a lot more realism. This is to be expected, since it is what happens in real life.

And this bit of simple logic or otherwise put genius, is why I am now addicted to these shaders. I can't imagine not using this on any render now. Heck I even tend to add parts of  this to stuff that is not even human skin just because it looks so much more realistic. I wish I could follow your logic better, I'd have it on every surface wood, stone, water etc.