Quote - I Dont render in poser so I never Gamma correct
But it seems like this GC/VSS combo is mainly for Figure portriats
showing alot of skin.
is it relevent to poser users who Do Sci fi with Mechs/machines etc?

Yes it is. It probably even works better, since generally non-skin shaders are not as complex, and don't have kludges built in to fake some of the effects of GC.