No problem Baggins.  I just get a little sensitive when ppl compare my shaders with theirs.  Most of the time they use favourable light and renders settings for their shader, which is not fair.

Anyway...Any SSS technique that does not take into account the positioning of the main light source is going to compromise realism.  I think your issue with the Incidence technique is that you need to run the shader again if you move the main light.  In practice I don't think this is an issue for more users, since they finalise their light positioning prior to running the shader.  Regardless, the next version of the product has a callback which automatically reruns the shader if the user changes the main light position.

Skin realism is all about having the skin look realistic relative to the figure's surroundings.  Shaders need to respond to the lighting and objects in the scene, otherwise the figure is going to look out of place.  "which skin looks better" comparison's that have the figure on a black background are not testing the shader in an environment that users will be using it.  The incidence effect starts to build a skin model that is reacting to the scene lighting.  If you want more realism, I think /simplifying/ the SSS model is going in the wrong direction.  You need to be building a shader than takes into account MORE of the scene information, not LESS.

Creator of PoserPhysics
Creator of OctaneRender for Poser
Blog
Facebook