Until you are into serious power and boost, the stocker should do just fine. The geral consensus about a BOV on an otehrwise stock WRX is that it is useless. I had a Forge BOV on for abotu a week. It got to annoying but when I would get off the throttle than back on it relatively quickly, I would get a slight buck. If you like it and dont have problems, keep it. It may cause the car to idle crappy or buck between shifts or lifting off the throttle.