I know this, if you ride a motorcycle, with a standard steel chain, then you ride on a cruiser with a belt instead, the vibration damping is almost distracting...the potential to smooth out the pedal stroke is nice, and the belts will last much longer than a chain, and stretch much less.
The down side, is they aren't good for the environment, being rubber and all. but outside of that, i am intrigued.
(I wish I had the testicular fortitude, to resist new gadgets on my bike, like NI, sometimes. :p)