I've heard a few and like Tarzan they all sound about the same. Each brand has a little different sound but they're all pretty close. A full system will sound different than a slip on and the piping material will also affect the sound due to resonances. I will have to say the GPR system on my SV650S sounds different than any other system I've heard on one so you do need to hear any system before buying it. Do a youtube search for it and you'll probably find a clip.