I EXPECT TO SOON. MY STILLEN DUAL REAR EXIT CAT BACK SHOULD BE HERE TUESDAY. Picking a exhaust is really a combination of need and want. I chose this exhaust because I PREFER a dual rear exit, even though performance wise a single side exit can deliver as much or more of a HP gain. I also chose this exhaust because I want near stock volume at idle, a little louder at WOT, a little deeper tone, and no drone issues. If you want pure power and a loud aggressive volume and tone, my choice would not work for you. The reports I have read say the single side exit Stillen has solid gains but is also on the quiet side, similar to the magnaflow. There are a bunch of good set ups out there, JBA, Zoomers, Magnaflow, Borla....They are all good at what they do, now you have to decide what you want.