I see a big philosophic difference :)

When you use Nurbs you know exactly the form that you want!
When you use SubD you don't know exactly the form that you will obtain! :)
it's always a surprise (good or bad :)

There is an interesting thread about that on SketchUcation! (34 pages growing of examples of what I say! :)
https://sketchucation.com/forums/viewtopic.php?f=397&t=63826