I can tell you that. I was unable to export the character material in a way that made it look like it did in Iclone.
Also, I had a problem with designing the hair system from C4D for one so that I can simply use it again. This is important when the avatar changes clothes. I would have to re-create the hair in C4D every time. I tried to detach the mesh with the hair from the head and position it on the new avatar. But it did not work. Also, character animation in C4D is much more difficult than in Iclone. In principle you can transfer the movements from Iclone to C4D. But saving them in the C4D library is not possible.
I still hope that there will be a direct link from Iclone to C4D one day. That would be the perfect setup for me. Create the avatars in Iclone or CC4 and then just edit them in C4D.
I only bought the computer to do some animation as a hobby. It is a good balance to my stressful job :-).
Many greetings
Peter