Indeed I'm not a tspline expert & I totally agree on that rhino is very slow compared to silo/modo etc. BUT there plenty of benefits for designer, perhaps not so many for Viz artists. ( I hope the new pixar engine for Modo will make things easier).

So yes SubDNURBS import for MoI would be great. The fact that the library comes from the same Co. as the engine MoI is using is a big Plus. (So lets hope we get it before Autodesk buys them :)