I'm not an expert by any means but the entire line of reasoning for that BOV ad seems off to me. Channel more air AWAY from the turbo between shifts? Ermm... the car is a dual scroll turbo part of what makes it a bit of a monster for a 4 banger is the constant flow of air back INTO the compressor. Confused...
As for WHY you would want a 400 dollar BOV----- "whooooooosh" nifty sound effect, albeit a bit expensive.