Has anyone tried the Powercore or the 4.1 with powerbomb head in SS? Is the 4.1 really worth the extra $$$. Most things Ive read say theres not much of a difference in the Powercore and the stock just wondering whos actually got them on their bike and if they feel it was worth it. Twisted up my pipe and header laying it down Sunday and looking to order something up but I was looking for some actual feedback. Thanks in advance.