Ok my $.02 and my opinion,
I am not an expert or a veteran, but I would like to remind supraman317 to ask himself, is sound most important? Surely the purpose of a BOV is not to sound cool, although can be frosting on the cake:icon_wink It is to reduce wear on on the turbo by releasing the compressed air that the turbo creates when the throttle closes and there is nowhere else for the air to go but push back on the turbo fins that where just trying their heart out to spin faster... then you get that "cool" flutter sound that is not so cool for a long lasting turbo.
I plan to use the Synapse/Synchronic, my research would say it is on the top end of functionality, sounds cool but not super cool :icon_bigg
Oh and I can't help it lol - :gotrice: