bantha:

Me to BB: when you say "roughness maps" (and that they don't matter much) do you mean displacement maps?

bantha: A roughness map would affect the roughness value. Makes the shader more or less shiny. Has nothing to do with bump or displacement, but in fact simulates nano-bumps.

That did not answer my question. There is no "roughness" node on the Poser Surface.

Can you please translate "roughness" into something an intermediate user of the material room such as myself can grasp?