I think MoI actually a good and mighty tool, for that Price, when you must go deeper in the Nurb-Surfacing-World you must use Tools like "Alias/Autodesk Class-A Surfacing", "Solidworks", "NX" or "Catia", but the prices of this tool are about 6000€-30000€, a year, a cheaper solution was the VSR Shape Modeling plugine (300€ 2012, I think) for Rhino, but it don't exist anymore, Autodesk has buyed it and now you must buy Alias A-Surface-tool, I think at now it costs 10000€ a year.
Here you can read the limitations of polygon vs nurb modeling
