Exoticspeed PWR-SI - that's what I have. Very quiet in idle/cruise, but loud when you floor it. Not many people here have it, but I love it on my car and I get nothing but good remarks on the looks and the sound.
This is an old picture - the system now comes with X-Pipe, otherwise looks the same
No dyno figures, but it's essentially modeled off of the Amuse system so go and figure.