Here is a comparison video between SLP and MACs. When I took the video for the MACs I couldn't really get on it in the parking lot as a a car was entering.
YouTube - 06 Mustang GT, Pypes Catted X, 12" Resonators, SLP LM
YouTube - MAC Axlebacks with pypes catted X and 12" resonators take 2
YouTube - 06 Mustang GT, Pypes Catted X, 12" Resonators, SLP LM
YouTube - MAC Axlebacks with pypes catted X and 12" resonators take 2