I put rush pipes on my F6B and am very happy a deaper sound nice rumble! But if you want piss your neighbors off sound out of a Flat 6 you'll need one short pipe per cyclinder make it look like a mustang fighter plane! and then tune the electronics for no back pressure and wear fire proof pants LOL This bike just really isn't meant for that kind of sound!
I will tell ya that the Rush pipes sound better than stock very Porsche like sports car sound