Hi Will, Well generally it seems like MoI at $200 will already be less expensive than nearly all the Rhino plug-ins that I have seen. It's just easier for me to focus on one product right now, I don't really plan on doing a Rhino plug-in anytime soon.

Cinema4D / 3dm - They might only support reading polygon mesh data out of the .3dm file. This won't work with MoI since MoI stores only NURBS data in the .3dm file.

By far the preferred method for export to Cinema4D is by OBJ, that actually works extremely well. The final renders of the OBJ imports have NURBS level quality since the vertex normals from the actual NURBS surface are used to calculate the shading.

XSI / IGES - kind of the same story, use OBJ. XSI theoretically supports NURBS directly but it just is not an area that they have focused on for a long time, it is best to avoid that and use OBJ import again with the vertex normals enabled.

- Michael