I have the HKS cat back, I considered at one time the Megan dp/tp combo since its 200 bucks for both.... What kind of sound do you get along with your HKS? I only have the cat-back and I'm looking to install dp/tp. But I'm concerned about the flow on the smaller diameter tubing used on Megan products. I would prefer 2.5 but Megans are 2.38.