I swapped around many different BPV's and now have a TurboSmart Dual Port 50/50 and the Forge Recirculating BPV. I have been running the green spring in all of the Forge vales. No issues at all. I peak around 27-28psi. I haven't really tested around 0psi like CO11WRX did, but overall I don't see any issues at all. And no flutter on throttle lift.