I have followed the joe lightning tutorial to  a tee making my own facial creation however whenever I import back to cc using the goz button and all button my completed mesh comes back white overlapping the original or inside however you want to say it. I did set the sub d back to 1 before exporting.

One thing I make sure I check when sending to ZBrush is to separate all parts. The make sure when you send it back to CC3 that all parts are visible and I do Visible. It has to check all parts to make sure they are all coming back as they were sent. Another thing is to make sure that you don't use the poly groups from UV or change any poly group for that matter as it causes it to lose sync with CC3 and will send you a character as a mesh instead of a update.