I got the Akrapovic axle-back, big improvement. That alone might be enough for you OP. I bought it from HP Autosport (Harold). Go to Vendor Classifieds and PM him, or PM me and I can get you his info.
UPdate: Akrapovic axle-back is now paired with the MadDad mid.
Not sure if I will keep the MadDad or not, it is definitely louder, but I feel like the Akra with valves open was possibly good enough for me. I will probably drive it for a few months and see how I like it. Previously, I started the car, opened the valves and drove off. Now, in many cases I leave the valves closed until driving on more open roads. I am always closed in an out of my neighborhood. Glad to have the button.