I am not C4D user, but I think C4D not support nurbs.
Many software for mechanical engineer usually base on nurbs. There are many software like solidworks, Pro-e, catia etc....

Even I have use nurbs base software before, I still like how MoI works. Very easy to use and work in moi like play a game :)
I am aware, there are also some areas like "dimensioning" that very important for me that MoI cant cover this now. MoI still in V1 and I wish Michael will provide dimensioning and advance surface in the future....

any way, I like MoI :)