I get something that looks like this:



Could you maybe be a bit more specific about which pinched areas you are worried about?

But it is harder to make a smooth shape this way, doing it with a fillet is the more natural method for NURBS modeling.

One thing that would help is to have a more gradual shift between your different profile shapes, for example these 2 profiles are fairly different in shape with a sharp bend on one of them, things like a sharp bend in only one profile will tend to not make very smooth and gradually curved surfaces from them as well:




Probably your best bet since you want some particular kinds of polygon output is to not use a NURBS modeler to create your shape at all and instead create it in a polygon modeler where you will be in full control over every polygon that is generated.


- Michael