For the general public.....................it seems how well it runs and sounds has much to do with the type of exhaust flow there, if a straight through type then it will do better, if the mod kills part of an exhaust 'loop' though you can get a much crappier result and most now use loops and splitting since that kills more noise in the confined space there. It's utterly amazing how simply defeating one loop can so open the outright noise up in some of them. On the F it was really bad sounding too, it had no basis in what a normal nice sounding exhaust sounds like, being a high flat 'blatting' sound that grated on your ears instantly.
The spark plugs actually got darker as well, meaning richer, meaning I LOST power there. I had a header for it within a week, no way was I gonna drive that new bike around sounding like that.
Honda wasn't kidding on the exhaust mod sticker on the bike when they said mods might hurt performance. Who knows, they may be setting those loops up in such a way that removing the easiest part actually messes the bike up worse, knowing how people commonly are.