The NURBS are working out all right. Basically, I'm just boolean cutting pieces out of an original sphere shape that I started from. I tend to exaggerate the details on my models because I do a lot of long shots. In close-up renders, my models will show all their flaws in glorious HD.
Once the pieces are cut out of this section of the ship, I'll convert it to polygons and fix any rough spots before I begin painting it.