Originally Posted by Zippy
The spec hits are something I'm still learning too. It's not so much the lighting as the surface. The standard surfacing needs its spec tweaked to work but it does. What I've found is nice is switching it to Principled and copying the standard surfaces (dif, spec, etc) into Surface layer nodes has kinda worked. The only bummer is there's no dif maps on Principled.
Ah ha! A clue! I shall have to investigate. . .