I want to revise my original comment on the sound...
Please forgive me for I've only driven it a couple of days and previously stated that I have experienced very little sound increase. I was doing it all wrong. At WOT and 3500+RPM there is a significant sound increase.. starting at around 5000RPM the intake burble and sucking sound starts to drown out my exhaust!
If you are
not at WOT, there is not much difference in sound than stock no matter what RPM you are at.