I was thinking the same thing. It must yield gains, maybe not as much as a test pipe, but something. Like ArthurJ said, adding a pipe would be ideal since it would pass visual inspection when it was time to smog check.
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."