I went with the HKS SSQV... Yes its more expensive, but you don't have to mess with springs and tuning it correctly by switching springs all the time. Plus, no one is really sure if the Forge is providing adequate or too much spring pressure against the piston during light loads/pressures. The blue spring seems fine for most people, but it still leaks slightly, the yellow spring is too weak, and the red is too firm...
HKS SSQV and Synapse Engineering are the only ones that don't use springs or adjustment screws etc; instead, the use the differential pressures to provide exactly the force needed to release the piston and vent. They are the fastest reacting BOV/BPV on the market... Plus, the added benefit that they can withstand any boost (1-7psi, moderate, 7-19, or high, 19-30 boost pressures) levels with zero leaks!!
I would settle for no less...
But thats just my opinion though...