We dyno'd the SS last night after installing the American Racing (Catted) system with stock mufflers. For comparison, we used my BEST stock dyno run...I certainly "could" have picked my worst stock dyno to make the gains look better and if I were selling a product that probably would be smart, but I'm "keeping it real" so you know what it really did. (all numbers are SAE corrected, Same dyno for all pulls).
My best dyno stock was 321rwhp/332rwtq, by best with headers + tune was 350rwhp/370rwtq for gains of 29rwhp at peak/38rwtq at peak.
At its maximum gain over stock it picked up 42rwhp @ like 5300rpm and 42rwtq @ like 4200 rpm.
I will put some sounds clips up soon. It is as quiet as stock with the cruise set @ 80 mph, but it definitely wakes up at WOT.
On my auto we didn't see the 50rwhp/45rwtq that was claimed (which I assume was on a 6sp manual car). However, if you figure dyno variation, weather differences between stock and modded pulls, and the different amount of power gained between manual and auto, I think my numbers are in-line with the advertised claims.
ADDED: video of 0-60 run after mods: