If a more efficient running engine, better gas mileage and more power is you ticket to cool, then you need to have some back pressure on the exhaust. Even an expansion chamber (like a burned out glasspack) will help.
I love the loud sound too. But when I drive for an hour in a vehicle like that (I'm used to loud Harley's too) I might want to listen to the radio, or have a conversation without the words "huh" and "what" with every sentence.
If noise or rapping is your cool, fine. But, when some of the kids in town can't afford to replace the muffler that has fallen off or rusted through, it is offensive when they rattle by my house at any time of the day or night. But, by all means have it your way. You'll pay for it later when "huh" and "what" are normal in every sentence of your conversations. If you don't care about what others think, it will come around to you eventually.
This isn't a "do gooder" attitude, it's an experienced one.
