I had Thunderheaders on an ultra a few years back, made my ears bleed and no one wanted to ride behind me... Now I have Vancin Hynes Monster Ovals - they have a low rumble and because the exhaust chamber is so large there is room to move the gas out to get better motor performance without the really loud noice... exhaust is personal choice - think about your riding style, hours, traveling pals and neighbors when making the choice - good luck!