I was told by an Upsolute (ECU reprogramming company) that to get the full benefit from an ECU upgrade, I would have to have a pulley set installed. He did mention both Renntech and Evosport.

The bottom line from this tech was that the pulley set will get you a little and the ECU upgrade will get you some, but both together will yield quite a bit. (I think he stated over 30 hp for my SRT6).