Gosh, you need bagginsbill for this!  :)

I do remember him telling me in a recent thread at RDNA that the Fresnel node should not be used because it causes double reflections. And that the fresnel effect should be accomplished with a combination of other nodes.

There was a thread here about diamonds which turned into a general thread about reflection including water reflection.  The water effect in there was achieved with the fresnel node, but apparently in that case, the double reflection (which wasn't known at that time), didn't matter because the inside of the tub was white and  double refletctions weren't really noticed.  Anyway, all I know is that he said after that, to not use the fresnel node at all for anything :) So I don't worry about that node anymore.

I also know that the Diffuse_Value + Reflect_Value = 1  Your example has them equalling 2.

I'm still working on learning all of this stuff too.  I dabbled with it before, but nothing serious because my computer couldn't do raytracing. Now that I have a new computer that can, I'm somewhat behind in learning all these great things :)

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi