A couple of things that I do notice, using Wall 3 as an example.

"Create Roughness Map" is checked by default. But it only creates a roughness map if there is a specular or bump map. The wall has a diffuse map only, and that diffuse is plugged into the Bump channel of the PoserSurface node. 

BUT ... GoPhysical doesn't create a roughness map from that, and the Roughness setting is set to 1 (I'm assuming it's expecting values from a map and that is why). But, because there IS no roughness map, a setting of 1 makes the walls look very flat. Setting Roughness to .5 give the wall a more satiny surface. The more you reduce the Roughness setting, the "shinier" the surface will get.

But the second part of this wall is that the GoPhysical conversion doesn't inherit the Specular Color from the PoserSurface node, instead it's 50% gray.