Well, to my enormous surprise was just that, on the contrary; it gained performance from around 2,500 all the way to 10,5. That is on torque (I did leave the baffle in on the muffler because on long ride, too loud) and around 6 she becomes even more happier. I have never experienced this on any bike from just those mods, not on any race bike of any type that I have competed on or owned(Road, Cross, Enduro, Quads, scooters, X-country) you name it. I also have larger dual tourers and same thing, none have taken these simple inexpensive mods so well and noticeable to the rider as the V.
On just Arrow full system, it comes with a dyno run and states 67.48 rear wheel HP, WOW. Add an air filter and even better, you can feel it big time. The best part is the fuel economy did not suffer, it got better; 130-150 km/hr and she still does 84 km/us gl. = 52.17 mi/gl. Take her light and she will do 55 mi./gl easy. Mine is a US model, same color as you guys, FYI.
PCIII, no need in my opinion, only on my big strom did I need it to help with the lack of fuel maps on the ECU (16 bit instead of 32) to smooth her out.
If you try this setup, I think you will be very happy with it, I started out just muffler, then air filter 'till I added the head pipe, then it all came together very nicely.
Hope this helps out