You are pretty much on the money with that statement. Synapse took hks's piston actuated bov design and improved it. The hks ssqv and the synapse bov are both piston actuated, but the hks still relies on a diaphragm to close the piston. The thing is that the diaphragm weakens with time. Ask the op, he had an ssqv and with time the bov was slower to release the excess boost pressure causing compressor surge. The synapse relies on a boost/vacuum signal to cause it to open/close. Along as you have a strong boost/vacuum source, the synapse will not weaken its ability to relive pressure.