I absolutely love it. I use it in my modelling process constantly, and have wished for it to work inside non supported editors for a while.
I am an interface nut, I have currently operational on my desk right now, the 3d mouse, a regular scroll mouse, an orbit trackball with scroll ring, a generic drawing tablet, a belkin nostromo N52, 2 gamepads, a wireless keyboard, a microphone, I-pad2 with custom keypad software, a Wii-Mote, and an Xbox kinect which currently just moves up and down to better track my face.
By far the most useful piece is the space navigator 3d mouse. theres really no way to replace its function except with another one.
P.S. still missing from my ultimate interface collection:
Cintiq
Emotiv Epoch