I came across this video where a Charger Scat Pack with a stock air intake was raced against another Charger with a cold air intake. The results? The Charger with the CAI had a slightly better throttle response (and sound) but, other than that, there was no real performance gain.
I don't feel using 2 different cars makes for a very good comparison. What they should have done was tried it again with the air intakes switched to the other car.