[RideWithDanger]

As others have said, S is louder than stock but if you want a loud exhaust its not really the best choice. It does have a much better, deeper, and more aggressive tone though. Better still IMO is the AWE Touring exhaust. Its cheaper but lacks the NPP function.

ATAK is louder than S, obviously, but keeps an aggressive tone but not quiet as deep.
If you plan to do any header work in the future, go with the S type. If you want loud and don't plan to do headers, do ATAK.

AWE Touring is a good mix of both worlds as its very loud when you get on it but also keeps a super deep and aggressive note when idling or cruising. Cold starts are a bit loud but thats true with the ATAK and most other options as well without NPP in stealth mode.