BurrMan,

I say "your wrong" only if you are wrong. Let me see my "false statements" pleas.

You still do not answer my question:
2. So any way if it is true sub-d modeler is it possible to import obj of any complexity without modification like retopology and modify them ?

>Michael, it's neat that NURBS have the underlying surface that can be recovered, however, as mentioned with the "Commit" becomes destructive, the translation of MoI's surfaces to other apps, will result in "Shrinking the trimmed surfaces", which would destroy the original intent and construction, and require further "special techniques" to do any type of repair.

If we are talking about Groboto, yes process are not destructive since it is inside it. But Groboto is not fully featured modeler that allows you to make serious projects. And you have to export obj, to finish it in Sub-D modeler like MODO.
Moi opposite is fully featured modeler that allows to make very complex projects. So no need to "Commit" at all... Every time you can change everything inside MOI and then re-export it. I work this way no problems at all...