I've been talking to a guy who wants to sell his slip on kit (carbon cans, ecm and filter) new for around $1300. He bought it for his 1098, but claims that it will fit and perform correctly on the 1198 and 848 as well. I checked the Ducati performance parts catalog and there appears to be different p/n's for each. Who here knows the real deal? Do these slip on kits make a big difference in anything other then the sound?