Edmund,

My experience is very similar to yours, although I don't recall testing STEP import in C5Pro.

In C5Pro I found STL to be the most reliable choice for importing from CAD software. IGES occasionally would produce acceptable results. VRML was acceptable ONLY if the object had a low poly count and I needed textures. DXF and DWG usually produced the worst quality import.

I have yet to try importing any CAD files in C6Pro, but if some import formats have been eliminated, this will be a problem in getting good CAD geometry into Carrara.

I'm going to try some CAD models in C5Pro and C6Pro for comparison. I will report any issues on the daz bugtracker http://forum.daz3d.com/bugs/login_page.php, and suggest anyone else needing reliable CAD file import to do the same.

Chris