Yes, it did give gains when added to a "2011 Harley-Davidson Street Glide equipped with a full exhaust system and a freer-breathing air cleaner but still running on the stock fuel map".I had a Power Pro on a Street glide and it did not work like advertised. Fuel milage dropped and did very little for performance. Called Cobra to try and return it and they said no. Guess that is the way it goes. Bought the Harley SERT and a lot happier. Save your money and get the SERT. Just my opinion.
Wish I would have read this article before spending the money. Lot of money for no more gains than it gives.