<<<< waiting for people to pick ret030 apart
Members will begin to tell you to search on BOVs and their adverse effects on our Subaru engines. Most people will ask why you would want to sacrifice performance just to have the cool "psshhh" sound. I'd ask the same thing, but of course it's your car so you do whatever you want to it.
Without proper, professional tuning, you will never know whether your BOV is actually hurting or helping your car. To sum up what people will tell you: you don't need one/a BOV actually hinders performance/it's a waste of money/true Subaru enthusiasts know only noobs keep BOVs on their cars.