I'm still debating on whether to go with a BOV versus the BPV (or diverter valve).
Since your blow-off or not-needed boost gets vented to the air, and no longer available during rethrottle, the theory I understood was that it keeps the intake boost temperatures down. The theory being that the cooler but denser air/fuel mixture creates more power.
I've noticed that some add a small PCV style air filter on the BPV line when installing a cold-air intake, while others will install a makeshift cold-air intacke or plug the (BPV) line when switching to a BOV.
I suppose with the BOV you could also buy a cold air intake system and build a 2.5 pipe to route intake charge via hi-temp silicon turbohose into the turbo eliminating the hose that routed to your bpv.....
I suppose a plug would be the quickest, but cheapest fix.
food for thought...
regards