I don't have dynos to show the difference if I'm not mistaken so I'm not saying it did. It did feel that way though.the system doesn't lose power, and even if by some chance you lost 5 hp, it would not be anything you can feel.
there isn't any system that we've seen / installed that looks like there is any reason it would lose power. Without a tune , with the same throttle response, car is going to feel exactly the same. Other than if it's pulling a bunch of timing for fuel, or really hot and pulling power.