I did a series of renders earlier in this thread showing the importance of GC with the VSSPR3.  It illustrated how dark skin can be severely affected if CG is not addressed properly in PoserPro.  My routine now is to leave CG on in render settings and create a new VSS prop with CG set to 1.  If you think that the original prop is impressive, try PR3.  It will really blow your mind.

Another thing, btw, try using IBL for your renders with using the VSS Prop.  It displays a much more realistic result than the regular lighting.  My convention is a 3 lighting system for starters. One IBL, one infinity for shadows, and one spot w/o shadows for fill.