I'm currently using an NN 3 with a Pentax K-5/Rokinon fisheye. I have the adjustments dialed in now to the point that getting good nadir stitch is usually not a problem. However, living in a large Japanese city, I usually head out to take panoramas on foot or on bicycle so keeping my setup as small and compact as possible is highly desirable.
For those of you who have used both the standard type pano heads and the ring-style, are you able to stitch your apex and nadir shots as precisely as you could with the standard NN3/4/5? Assuming you not changing lenses, are the R1/10s a compromise? Is it more difficult or easier to achieve equivalent results?