My previous bike was an SV650 with a shorty can. Man, that thing was loud as heck when you opened it up. A guy took it on a test ride when I was selling it, and I heard him open up the throttle two blocks away. Unbelievably loud. Almost Harley-like.
When I test drove my 9er with stock exhaust, I couldn't believe the quiet, even when I cracked open the throttle. To me, it seemed like an amusement park ride -- just "whooosh," a rush of speed with not a big racket accompanying it. I'm really digging the quiet ride, too.