I bought my 04XB12R simply based on the torque and sound it made with that D&D exhaust.
With that said, my D&D Exhaust broke a few months ago, I shot an e-mail off to D&D in Texas and long story short - they sent me a brand spanking new exhaust in exchange for my old one, no questions asked!
During the wait, I put the stock exhaust back on, what a shame that the Buell was shipped with such a wimpy little exhaust. It sounded like a spree!
I got my D&D exhaust back in the mail and installed it, it sounds better than ever!!!
Very impressed with the exhaust, VERY impressed with their customer service too....
-J