Thank you for a good explanation Michael

If your plugin allows you to change the edge weighting (some PowerNurbs products do allow this, I suspect that's what you have?) you might change the weighting (if you have not already tried this) to allow a creased/sharp edge on the corners you want to fillet in Moi.

Chris: Interesting proposal. I will try that.
Do you use PowerNurbs as well?
In my (very limited) experience there doesn't seem to be a great poly-to-nurbs-workflow. Might as well start making nur bs right away...
...Or perhaps Im doing it wrong.

I've tried the plugin for SolidWorks. The huge advantage in my opinion is that you don't have to create curves & sections to generate a nurbs surface. You can manipulate points, edges or faces on a surface right from the start to get the shape you want, its much more direct I think, and can save quite a bit of time for more organic stuff.

I never had a chance to play with edge weighting (my demo expired), but it seems like it could be very useful for objects where you want a combination of hard and soft surfaces with smooth transitions (blends) between them.

"The huge advantage in my opinion is that you don't have to create curves & sections to generate a nurbs surface. You can manipulate points, edges or faces on a surface right from the start to get the shape you want, its much more direct I think, and can save quite a bit of time for more organic stuff."

I totally agree with you there. A way to get the best of two worlds (at least in theory). However I don't feel Im getting the results I was hoping for. But Im still fairly new to 3d in general and might need to experiment some more to get it right.
Ive tried to use Fusion 360 for the conversion instead, and that seems to get me slightly better results I think.