I have been watching all of the exhaust videos I can get my hands on, and I have narrowed the search to Active Autowerke's and Super Sprint (sport)
I am going for a mellow, deep sound... I guess just deeper than stock. Can anyone give me a recommendation on which one I should go with? Need help before I drop all that cash!
Thanks!

I wish I could say I've heard the SS exhaust.

I have the AA on my car, along with headers, cats, and Eisenmann Section 2. The sound is spooky. Very raspy at cold start, mellowing to a roar when the car reaches operating temps. At 180 degrees, where the car usually runs thanks to the cooler euro headers, it still has a tiny rasp but plenty of roar. When I run the car hard it goes up to the mid mark on the temp gauge and the exhaust changes again, to something that bystanders have told me approximates a track car. My own impression is that of a large cube race bike.

The AA is very well built, very attractive. The tips get lots of compliments, when I remember to clean them. :rolleyes It makes a nice combo, looks-wise, with the Eisenman pipes. A month after I received it, my Racing Dynamics X pipe still sits in the garage waiting for a tryout. Maybe it will replace the ES2 pipes and I'll have a different sound report for you.