i don't know about OBX, but lifetime warranty can't be a bad thing.
i've had Megan Racing headers on my 2000 LX Sedan, but i had fitment issues between the flex pipe and the cat which made a small leak. it was driveable, but sounded like a lawnmower when you neared a wall, it was barely noticeable.

now i ride with DC Sports ceramic header. costed me a bit more, but saved me from the Megan Sport headache.