I don't have a way to compare, since this is how I built the car from the begining with the LS1. I knew I wanted to do it from the onset basically, of getting cooler air into the engine...just didn't know for sure how I was going to do it until I actually made up the template for the box

I can watch the IAT with my handheld OBDII tool, and would be interesting I guess to compare to a car with just a 'normal' underhood air filter.