For people who choose the exhaust for BMW S1000RR

So I've been on the hunt for an exhaust system but there are so many options. Some systems I really like are the Akrapovic full system(the stainless steel one cause the titanium one is really expensive), and then also the shorty Arrow full system. I like the arrow because of its low mounting position and the fact that it comes with the DB killer so you can take it out or leave it in. Which one do you think would make more power.But you can watch this video, I hope it will be useful for someone else!