There are nearly as many opinions here regarding exhaust as forum members.
I had a similar dilemma about the AA signature exhaust than you have. I wanted more "noise" on the track but not in the hospital parking garage. I use the M3 as my DD from March to November. The AA rear section on it's own is not loud at all. Around 3-5000rpm it is like stock. It is so not loud that now I consider the AA X-pipe with cats.