If you are willing to pay, akrapovic exhaust products imo will always be perfect in regards to user expereince. flanges, alignment, slip fit and bolt holes are always absolutely spot on. Ive used akrapovic on 3 of my cars and now my bike. if you bought the slip on for the r1 you will be disappointed that the bike still sounds like a moped down low. You are going to need to remove the cat to get what you are looking for. Make sure you follow up with a tune and block off plates (which can all be sourced on this site). Would love to see them stock some bellypans on the STG website.