All right, I've got some good progress on specular highlights also now.

Here's an example:



Here's one with the metallic option also enabled:



When you enable Specular highlights, 2 additional sliders appear in the UI that let you adjust the Brightness and "Focus size" of the highlights.

Here I've taken the above one and loosened the focus and dulled the brightness some, it gives more of a sheen to an object rather than a hard looking small spot:



- Michael