Hi Jay - Spud is spot on - the stock muffler has a catalytic perverter (
) at the bottom of the muffler. If you look into the muffler, you'll see the honeycomb at the bottom of the muffler closest to the inlet.
The Akrapovic muffler will give a deeper tone and may be slightly louder. But it incorporates a baffle that can be removed and, upon removal, it WILL be louder.
I am taking the stock muffler (as a template) and the Akrapovic muffler to a muffler shop in the AM to see if they can bend pipe to match the stocker. That way, if, for any reason I'm not keen on the Akrapovic sound, I can always re-install the stock pipe.