Quote - . If you absolutely need hi-res head modeling (down to the skin pores that you want your camera to focus on), ZBrush is for you.  If you like working with lightweight models that are not RAM intensive (that are to be used for medium shots and for use in your scene's background), 3D-Coat is for you.

I'm not sure if I do agree. 3DCoat would  be vey usable for the situation you describe. It can do both..... high res for close up and medium and background. 3DCoat isn't for retopy only. You can model very detailed things with it and never use retopo. It depends on what you need. Low res? use retope. High res? use voxels and the other great tools 3DCoat has to offer. If you have 3DCoat and suddenly need high res very close up stuff, no need to rush out and get Zbrush then. 3DCoat has all the tools you need already. Both worlds for less money. 

Artwork and 3DToons items, create the perfect place for you toon and other figures!

http://www.renderosity.com/mod/bcs/index.php?vendor=23722

Due to the childish TOS changes, I'm not allowed to link to my other products outside of Rendo anymore :(

Food for thought.....
https://www.youtube.com/watch?v=pYZw0dfLmLk