Purpose?
OK. So they're saying that if it gives any advantage over stock, it will be a small one.
What is the purpose of this pipe then? Sure its quiet, but is it worth spending that much money on something that barely beats stock performance? If it were my choice, I'd just stick with the stock pipe and save myself the money.
I run the MegaMaxII on mine. Its quiet enough for trail riding, and has a decent power gain as well. So far, I am happy. The quality could be a bit better though. My silencer is starting to separate from the fitting that attaches it to the header, and of course, it cannot be welded. :(