The "advantage" is if you use the vents, you do NOT route any breather tubes back into the throttle body. I have to say I love mine and it puts the SE to shame. As it should for its cost. I have the lined cover also.fillinjc said:Upgrade time for my 05 Deuce. Sounds like Doherty PowerPacc is one of the best choices for AC. Now the question is Powervents or no. Guess if I had an oil misting problem I'd know it. Is there an advantage to spending the extra $?