First off, let me say I'm sure Corey's headers are far superior than OBX (not just the fact that they are produced in China).
Quality product from a QUALITY ZR-1 tuner in the US!!!!! Bonus!
As far as saying OBX / Stainlessworks headers are going to give you far less "RWHP" or MPH (in the quarter mile) is doubtful.
Brad is comparing two different cars and not the "same" car. In order to get a true comparison, you must install OBX/Stainlessworks and dyno the car. Then uninstall and reinstall Corey's headers and do the same test.
I have StainlessWorks headers (relatively happy with it), but if Corey was making his a few years ago.... I would have purchased his!
Love to see a "true" test of all of the headers....
David