Ah okies, I am indeed using the photoshop plugin. Yeah, would be nice to have the metallic system in there, however I will try and darken my diffuse and see if I get a more metallic look.
Just trying to get used how they work and how to get the best results, heh. I guess cranking both r/g channels and making it fairly dark in the diffuse should give you a metallic enough look. Shame they didn't implement a UE4 style metalness PBR :( The blue channel does nothing, you only ever have any kind of information…