I have also complained about NURBS derived models. The quick and dirty methods of conversion look to generate triangles and lots of them where sharp bends occur. Poser likes quads better than triangles. Poser can not easily smooth a triangle (if it can at all). A quad can flex. If I understand it, NURBS are great if they are used in a program that can render them also. (A lot of detail, small file size, ease of shapeing) But it takes a lot of skill and a lot of editing to get them converted to Obj and be something that is practical to use. Most of the time it may be easier to start in vertex and stay there.