My ER charge pipe and Synapse BOV is for sale as I'm parting out. Never had any issues with the synapse and I personally think it sounds better than the Tial and HKS. Haven't heard the Turbosmart though. Also keep in mind the volume of the BOV is dependent on how much boost you are running. I found the synapse to be quiet on stock boost but it sounded a lot more aggressive when I was spraying meth... With a lot more boost
