Now he's getting into it!
With these new networks, Mental Ray proves it has the flexibility I'm looking for and really outshines VRay. The VRay equivalent simply doesn't allow for the complex layering of shaders (especially Ambient Occlusion shaders) based on texture maps in the manner I need. The results in VRay are washed out and order-dependent. Shadows and Global Illumination in Mental Ray can be a real pain, but the opportunities are just too great.
The real problem, however, remains: What to do about fur?