Here is a photo of a Jet Pro replica pipe[snake/wave/s-bend], fatboy and a stock pipe (Stock pipe varies but they are all generally very shit).

Snake pipe - top, Fatboy - middle and stock pipe - bottom.
Stock pipes do not help performance and limit the cag engine alot. I recommend you upgrade you pipe ASAP. Upgradiing your stock pipe is one of the best mods you can do, add some fibreglass reeds and an advanced timing key and you will kick the ass of any stock cag.
The fatboy is best for longer tracks as it is a top end pipe.
The Jet Pro rep pipe packs alot of punch in low-mid range, so it is best for smaller tracks.
The stock pipe is.. well the stock pipe is best for the bin.
Just to let u know if u plan on getting a two peice headkit such as a 13:1 or 15:1 you will need to get the Jet Pro rep as the fatboy will not fit with a two peice headkit, the spark plug gets in the way.
Hope this helps all of you!
Regards,
Rob Wright.