a better way to get good result from the SSS shader with final gather is to use it not with hdr images, but with area lights.
i make, a studio area light not emitting spec, as the key light. another area for fill light. one directional for back light one ambient for flood light. another ambient with a negative value to suck out unwanted lights to give an illusion of occlusion.

you renders look really waxy and over blown. i think a regular shader will look better.