The problem I find with doing IDL renders, is that while the lighting is great, it kills all skin specularity. The only way I can overcome this is not through skin nodes, but with a specular light in the scene. Otherwise skin looks flat and lifeless.

It's ironic that SSS has re-introduced the old devil of nostril glow. Not really glow but SSS translucency makes nostrils too well lit. And AO nodes can't fix that, for reasons that bagginsbill would understand much better than me.