Hrm, sounds like this device is the same as the "manual ball bearing boost controller". Only, one end goes out into open air. Hrm.. Possibly save yourself $108 and use of those.

Plus.. can even splurge and get some $1.50 Kryogen paint and spruce it up a bit..

 

I wouldnt.. well it wont hurt. but it wont help either... a bov or a popoff valve releases the extra boost into either open air or piped back into the turbo inlet.. It has quite a large diameter and quickly releases "dumps" the pressure. see when your hard on the boost and release the throttle quickly, the turbo spinning at 75,000 rpm or so is still pumping. This all piles up in the boost tubes as the throttle is closed. the backpressure makes your turbo screetch to a stop. When you get back on it you have to wait for the unit to spool up again "turbo lag". The popoff, bov, or dump valve solves this problem and eliminates lag. you want one. trust me!