Hmmm, that's interesting. I can not think of any logical reason to feel a decrease in power, especially in the throttle response area, other than something installed wrong or the battery thing I already mentioned. I can understand not noticing a difference between the 2, but to feel a drop in your acceleration doesn't add up to me. Unfortunately this is one of those instances where there is no way to find out why, but I wish I knew, because it going to drive me crazy wondering what the issue was!
Well, enjoy the Camaro man, and take care