>They also say the retopo in Zbrush, while good, is not great. Again, I believe them. Perhaps you can share some of your work >and we can ask questions about it?

Normally i don't like to do that, but o.k.. Here's one simple example of a logo design made by a professional Designer and messed up, so that it could not be 3D printed for his client. I, as a hobbyist, reworked the design, so that it could be 3D printed.

As you can see in my picture i used a much higher mesh resolution in 3D-Coat than in ZBrush, because 3D-Coat gave worser results with an equal polycount. I also run several tests with 3D-Coat with it's various settings, to see if maybe one setting would result in a better mesh. The second picture shows where the 3D-Coat mesh is faulty, compared to the ZBrush mesh.
The ZBrush mesh was remeshed with it's default setting and needed only one try.





Best regards
Stefan