E-Series quiet core?

[01ytrx400ex]

Well i finally put on the e-series slip on pipe, Wow is it loud! Nice power though. Has anyone installed the quiet core? How much does it help? I know 5 to 6 db but is that seem huge? How about any power loss?

Thanks group!

I have it and took it off. It seemed to rob power and make throttle responce slow.

[Winged Warrior]

I hate the stinkin thing , my wife made me buy it,her and my neighbors love it. Yes it does rob some power and boy is it quiet .Im thinking of modifing it some?:grr