Time to throw out the Layer Weight node and start using this, a custom Fresnel node. When it comes to making materials in Cycles, the built in Fresnel nodes just don't cut the cake. The settings are just too limited and non-physically accurate.
I can't take credit for the inner workings, but I did create the node and the 3 shaders also included inside the Blend. The settings for the node are pretty easy to figure out, so I won't explain them. You can use this just like you would the "Layer Weight" or "Fresnel" node.
I also included three simple shaders to show how easy it is to get nice shading with this node.
Sure, here's the link: https://www.youtube.com/watch?v=6pJrlEzbNek
This isn't really any "better" than the built in Fresnel, as this is based upon it. But this gives the artist more control without having to add a bunch of nodes. Normally to archive the "Facing Limit" you would have to add a "Color ramp" or "Color Mix" node and change the values. And everything is done with math, so you don't have to worry about human error.
In your group node you put a "value" node labelled "root" with the value of 1, providing no effect ( x^(1/1) = x ) That should be removed and the "divide" node should be connected to the "power" input of your group, as explained in the video of CynicatPro.
Oh! Dang it! Thanks for pointing that out. Uploading corrected now...
Do you have a link to the original inner workings? Or at least an explanation of why this is better than the built-in fresnel?