I come from an AutoCAD background since R9 too.

I haven't however used Rhino much. But I have heard that Rhino is more suited to being a "engineering" package than not. It is from what I know about it pretty awesome but it's drawback might be it's data weight. Not a problem for building protoypes and modeling 1 specific object to a high detail but for on the fly modeling and integration with the core DG that is MAYA, I believe MAYA's NURBS are pretty awesome in comparison to other packages.

Personally I wish that they had bezier splines in MAYA as for generating simple fast shapes there is no substitute.

MAYA is "quirky" feeling after coming from packages like Acad and MAX per say,

Good luck,

JB