It's pretty much the same as MBEPIC... SASKINS just installed his on Friday and we met out at the track yesterday... I had an additional straight thru baffle installed before the muffler because I was concerned that it would POP too much... The car sounds incredible now, but the interior noise is a bit more than I would like for long drives and will take some getting used to.
It was great on the track but a little annoying on the 1.5 hour drive on the freeway to and from the track... Be advised, my girlfriend, who had not ridden in the car since I put the Magnaflow on, said to me while we were driving to the track, "What's that buzzing sound from the rear, is something wrong?". I had to explain...
I have a DB meter and some pretty good microphones and will record the interior sound while shifting thru gears since MBEPIC already posted exterior idle and rev sounds...
As far as the increase in HP... I have no clue... I got my *** whooped by a bunch of superchaged and turbocharged japanese drifters yesterday at the track and realized for the first time how underpowered my car is...

HELLO SRT6