Just got back from my first ride with my new FMF Ti-4 slip on and Uni filter. WOW! Sounds awesome (loud though) and has more bottom end, similiar mid-range and more top-end. Hit the rev limiter more easily, lofts the front end out of corners more = Big time fun. I love this bike. I would highly recommend this combo. The bike simply rips through the gears with much more authority, and has a better spread of power overall.