[Alpine TSi]

Sound, price, and functionality. I run the Paul Walker special(aka Greddy Type S). I like the not so screaming sound that it makes, but it is still loud enough to scare off the occasional ricer. It have pushed it up to about 35psi on accident and it has held just find. Plus when I needed to I could recirculate, there are some BOV's you can't recirc(ie Tial). You need to get one that will match your setup and your goals. Most of the high boost and power applications use a Tial as it is very stong and also pretty quiet. I am not planning on pushing an assload of power, so I didn't think I would need a Tial. The only thing I wish I would have known before was that the Type S came in grey, instead of the gay purple I have now.

Also keep in mind that a properly crushed 1G BOV will hold about 25 psi, I have seen that you can even mod them to hold just as much boost as a Tial.