I got a chance to try my PMB endo/spark arrester for the 08' shorty exhaust and am happy that I bought one. The 08' endo is a bit different than any other PMB that I have seen, as it comes with a removable silencer cone.. which mimics the stock exhaust(but looks less restrictive from stock). The diameter of the opening of the PMB endo looks larger than stock by about 20 percent. I have only had a chance to use the endo without the silencer cone but with the SA screen installed. Riding the bike without the silencer cone but with the spark arrester screen in had a noticeable increase in power and sound. Revs out a bit longer and has better low end, by the seat of the pants. I would guess that it is 100 db without the silencer cone, but surely a lot quieter than an open mx exhaust. I would guess that there still would be a decent power increase using the silencer cone insert over stock, as the design looks less restrictive, but have yet to try it. The PMB endo is a relativly inexpensive fix for the shorty exhaust, not as performance oriented as a full exhaust but isa good option and has adjustability. Yoda'