Not too sure on the 1100, but on the previous generation Monsters, the difference between slip-ons and a full Termi setup is night and day when it comes to performance and sound. When I first went with the Termi setup (DP ecu, airbox and slip-ons) I found it louder but performance gains seemed minimal, though it did smooth the bike out and made it rideable. (many threads about S2R1000 issues). After getting rid of the udder and going to a full system and tune - wow. Completely different bike. Loud? very
