For only upgrading the mufflers it sounds surprisingly different, and in a good way too! It has a very nice, deeper note to it now and the good thing with Screamin' Eagle is, it is still under the legal decibel limit (street legal). So you can rest easy as you are riding next to one of those pesky highway patrol officers. Since the Slim S comes with an already blacked out exhaust, we saved money by not needing to purchase a set of black header heat-shields. And saving money is always a plus.