Alright. I got the muffler in today. All I can say is I'm glad I got the Quiet Core 2. I dropped it down to 5 discs, spark arrestor, and the insert. It sounds great. It doesn't have the raspiness of my Powercore IV, but it still has some really decent bark, without being too loud. I ran it up the road for a few houses to see if I could feel a difference. It smoothed out the hit on bottom a little and took out a little of the bog. But, I felt no power loss whatsover. Can't wait to get it Db tested. I'm sure it'll pass. Anyway, just thought I'd update you guys.