I have the H&S 4". I am happy with it. I just help install a 5" H&S, Very different tone. Deeper. I havent heard the BADP other then on the web. The difference in price is the Aluminized (H&S) vs Stainless Steel (BADP). Some say the tone is better with the SS systems due to the fact that SS is denser then the Aluminized.