Pure excitement. I have had the setup installed for 2 days, and I seem to have forgotten that my car is equipped with a radio. I drive around with the windows down listening to the exhaust burble when easing of the gas the beautiful distinctive hum it makes. I have never heard anything like it. It sounds like a muscular European automobile. I am very pleased. As far as power, I noticed quite a change, more on how responsive it has become. Just thought I share this with all.