If you don't connect to the sensor do you still get choppy results with rotations?
Code:
import viz
import oculus
import vizcam
viz.go(viz.FULLSCREEN)
hmd = oculus.Rift()
piazza = viz.add('piazza.osgb')
vizcam.PivotAnimate(pivot=[0,1.8,0])
What is the framerate when you have this rendering issue (press F4 with script running)? Do you have the latest drivers for your graphics card?