Like Ortho mentioned above, I initially installed the Slip-on and it definately was pretty loud and bassy on start up. It acttually drove my wife nuts when I left early for work. The exhaust note was pretty bassy as well on throttle blips but really became drowned out by the engine/ intake noise when getting the revs anywhere above 4k. Last week I completed the full Evo with the front section and I do feel that it somewhat decreased the bassy sound. The front pipes add some rasp to the exhaust note and really comes alive when WOT. As far as drone goes, the slip-on had a nice bass sound in the cabine at around 3k and I could see how that could getting annoying. I feel with the full evo that bass now starts at around 2.5k rpm but rapidly tapers off and is followed by a nice raspy tone all the way to WOT.
In regards of power. With the slip-on I could not appreciate any change in the pull of the car but with the full evo there is a significant increase in pull espcially once you break 5k rpm. The car feels like a completely new car.
2011.75 E92 MW/BB extended,ZCP,ZP2,ZCV, IPOD,BMW APPS, Heatedseats,6MT, Edition Black Chrome Grills & Side Gills, CF splitters, CF performance spoiler, CF mirror caps, Turner black anodized pedals, Akropovic Evolution exhaust w/CF tips, Still Undecided on tune, AFE Pro5r, AFE intake scoops, LUX H8
2009 E92 JB/Black 335 xdrive (retired)