to the board . . .
Dump pipes seem to have a bad reputation among people who don't have them. Keep in mind that your turbocharger itself muffles noise somewhat, making turbo bikes with dump pipes not as loud as a sidewinder, or Brock pipe, or other loud four into ones that nobody ever seems to be concerned about when it comes to noise. There are a million Harleys out there that are much louder than turbos - they are probably the most annoying bikes on the road when it comes to sound.
The bottom line is this: a turbo bike with a dump pipe is not as loud as you think. Also, you can be as annoying as you want to sometimes with anything - its all in the wrist . . .