I updated this one a bit. I decided to use a spec pass from both Cycles and BI. I used Cycles for a broad soft spec, and used BI for a few harsher highlight specs. And Kent was right, it's really hard to try and keep the spec passes subtle.
I also set the scale of the SSS differently for each layer, with the backscatter being the highest and the epidermal being the lowest.
I composited the passes together in Photoshop, as it gives me more control over each layer.
