Just to clarify for anyone reading this thread that is unfamiliar with how BOV and BPV work here are a few key points:
* Blow Off Valves (or BOV for short) can be used as "Vent to atmosphere". Meaning they release pressurized air to the atmosphere when opened.
*Most modern vehicles use MAF (Mass Air Flow) or MAP (Manifold Absolute Pressure) and sometimes a combination of both to determine the amount of air entering the engine for fuel calculations.
*MAP tuned vehicles can generally use vent to atmosphere type BOVs just fine.
*MAF tuned vehicles or MAF and MAP combo vehicles are much more sensitive to "Vent to Atmosphere" type BOVs.
*Most BOVs can be used in a "recirculating mode" making them fine to use on MAF tuned vehicles.
*Some "Bugeye" 02-03 WRX vehicles use or can use MAP only tunes, making them more lenient to airflow modifications such as vent to atmosphere BOVs.
*Some BPVs or BOVs are available in "Hybrid" types which offer partial vent to atmosphere and partial recirculation for better driveability (The COBB XLE is like this).
There are tons of other factors that should be considered when choosing parts for your car. As with most things in life, the right answer for some is not always the best answer for all, so the best thing to do is to read up, educate yourself and don't be afraid to ask questions.
Bottom line is that BOVs work well for many people, but can introduce complexity if not setup correctly.
Hope this helps!