my buddy just had these installed...and honestly the video DOES NOT give a true account of just how friggin loud these D&Ds are. I have D&D on my Buell Lightning...LOUD! The 1125r D&Ds have a shred as heard in the video but it is scary! It's a nasty sound like something is chasing you in a horror flick. My buddy sayz it def changed the curve and throttle response. IF you want the nastiest sounding pipes ever devised by mankind...GO D&D. They're mean, pissed off, and perform. They are badass.