This is an art content/art direction issue and has nothing to do with PBR or any technical aspect of rendering. Whether you make boring or interesting content is entirely up to you.
I wouldnt really call PBR a "tool", its a rendering pipeline. You can put whatever you want, however you want into it. How good it looks regardless of workflow is entirely dependent on the artist, like always. Literally the way I produce content has not changed at all. I still make my spec/gloss the same and my color map…
If you're working with a PBR system, it's always two parts. Its shaders, plus art content. You can break PBR conventions in both a metalness and specular workflow. For instance, you can use a bright albedo value and a partial (gray) metallic value and break the metalness workflow in the same way you can break the specular…
The white edge issue at transition with the metalness workflow is well documented (see here: http://www.marmoset.co/toolbag/learn/pbr-conversion#metalvspec) however, yet again this is not a "PBR" problem, its a texture standard format problem. You won't get the problem with the specular workflow, however, you will the…