I just picked up a 2017 500 exc and was looking around at different slip on options and it doesn't look like there are many at this point. So far it looks like FMF is the only option. According to KTM's U.S. parts catalog Akrapovic does not offer a slip on for the 500 exc. I have found the Akrapovic listed in other parts of the world (europe, australia). Why isn't the Akrapovic available in the states? Does it have to do with emissions? I've always ran Akrapovic on my bikes due to lower noise (db) but a deeper sound. I could get the Akrapovic if I really wanted to, but the FMF is more readily available. What's everyone's thoughts? Who has used both and has an opinion on which one sounds better? I'm not looking for louder, just a deeper note without any rasp. Powerwise, I could care less, the 500 has more than enough power for me.