I have had the ME kit on for about a year and a half. I hate it, LOL. Really I wish I would have left the stock muffler on or had gotten a flow through muffler. I notice quite a bit more noise in the cab, and ZERO performance gain for me. It may make a difference for some guys, but I have basically zero lag anyway, and I can overpower the stock TC at will. It does sound pretty cool, but running 1000 miles a week +/- a tad it gets old. I never had any EGT trouble, so any gain I saw in that department was a waste. I honestly did not see more than a 50* change in EGT, I did not see any faster spool-up. The only quantifiable difference I saw was noise went up. A 4" exhuast is in my near future, WITH a muffler, LOL. Save your muffler if it is possible at all, so if you don't like the ME you can put it back. Mine was destroyed for the most part in the removal. Everyone has a different outlook on it, I would advise you to put the ME on and try it. LOTS of guys are happy with it.