In principle images with GC should look better:

http://en.wikipedia.org/wiki/Gamma_correction

But, the proviso relative to Poser, as I undertstand it, as Laurie has explained more fully, is that this is only true if the sub elements of the scene, shader nodes, lights etc. are not already set up in a way that is designed to compensate for a lack of gamma correction...

...otherwise you will be double-compensating (as that's what Gamma Correction is... a correction, or compensation).

Cheers ;-)