Here is the scoop.
To me they are perfect. I can go easy on the gas and get past the cops and let the neighbors sleep or nail it and get that nasty funny car wail. Love the sound when backing off the gas quickly too. Best of all I picked some more HP and torque, instant throttle response.
Word of caution though, if you don't like good loud don't get them. Cruising, your girlfriend won't complain, on the gas forget about conversation. For me I grin ear to ear when I pull it back in the driveway and shut it down.