I think this should have been posted in the C4D section :)
Still, to answer your question, I think nodes aren't close to production ready yet - I mean the whole plugin isn't but nodes are still pretty much in the early development. I think it would be really useful if you'd post this under bugs / features in the C4D section so that the devs can have a better idea of how to develop it further.
As for the material node solution as a whole... I'm obviously excited they tackled this issue but personally I'm even more excited for Maxon to open up the R20 nodes SDK aso that the devs can implement their stuff directly in there.