Quote - Trying not offend here - but probably will - sorry in advance.

All the renders of faces in this thread look like plactic people - useful for cartoon work but nothing anymore serious.

To GC or not to GC? does anyone have any renders of faces with good face maps and variable skin texures that use GC?

Apple_UK, take a look at AtlantiStyle's products in the Market Place.  His textures are very realistic, and his sculpting skills are exceptional.  In my opinion he's a Michelangelo of digital art.  Let me know if you like any of his products.  I happen to own both Basile and Andre so I can probably do a test render of non-GC and GC images for you.  Below is the link to his product page.
 
http://market.renderosity.com/mod/bcs/index.php?vendor=483952