[2LZ]

Sound: It sounds about the same at idle. Maybe a tad more aggressive.
On the rev, it's got a growl but not too bad at all. Like I said, the stock muffler wasn't quiet when you open the throttle anyway. It does have a nice sound, when on it, more "performance" sounding....but come on folks, it's like trying to make a V6 sound like a V8. No amount of piping will make it sound like it has more CC's. You back off at cruise and it stifles down some. Livable for sure to me.

Power: Non-Scientific seat of the pants "Butt Dyno".
Quicker throttle response in neutral. Snappier.
Actually able to roll it on without dropping a gear under 5k! About 4-4500, just start to roll on the throttle (not spanking it) and it will catch up with itself! That's an improvement. These normally have "zero" under 5k.
After 5-5500k....marked difference. Between 5 grand and redline, definitely more crisp and more pull. Actual acceleration. Not like "DUDE! IT'S GOT A BLOWER!" kind of acceleration....but it's come to life. Not near as much "BUUUHHAAAWWWWW" when you hit it after 5k.

Cruise: Less throttle needed to maintain cruise. More crisp response.

I'm still going to tune with the baffle some more. I think another set of three holes.