Yep, I agree with Next Design.
Theres a real tendancy to over cook a model with Zb or MB. I really go balls out on the main model and get it as near as damn it before committing to hi detail which gets turned into a map anyway.
Im working on some characters for a pilot tv show at the moment and the VFX director asked me to sculpt the characters in zbrush and make them loo chisled, I put him off straight away as I could do it in the mesh with the arsing about. I did it of course, the mesh is lighter and the rendertime is quicker, and the edits are far easier on character design changes. Theres too much emphisis on super hi detail, the human eye cant even pick it up at 12inches on a normal day unless you are looking for skin pores LOL