Hiya, I have stayed stock with the exhaust. The official Akrapovic slip on is expensive and as big as the stock one and from what understand its a lot more involved swapping exhausts on the 2017 as its Euro 4 and you need a RapidBike module as Power Commanders won't work on them. I may eventually do it and get a full system but for now I am pretty pleased with it. being stock-ish. I have evotech bar ends, Puig screen, evotech tail tidy, HP rearsets, a Garmin satnav mount and a Hepco & Becker sportrack which makes it comfy and relatively practical as a very fast mile-muncher