That sound is just indescribably epic. It should never have been banned - imagine what flat-track would have become! I'm a huge fan of Harley flat-trackers, but god DAMN that thing is just too cool for comparison. I sincerely believe that that's the best noise I've ever heard from any engine. I hate to say that because the 120 sounds incredible as well, but the radical craziness of that thing... it's just too cool for comparison.
EDIT: Hey cool, I recognize Kel Karuthers there from On Any Sunday II.