Back in 2007 you guys had a thread : http://forums.vwvortex.com/showthrea...e-review-(long)
My personal observations was in line to original poster to some degree. I felt delay in reaction time when use Forge larger valves.
So, I had a major go on FORGE blow-off valve.
I was chasing a phantom engine power flactuation during the throttle drop from WOT to 50-70% above 5000RPM. It would cause engine power to surge, very annoying.
So, I machined a new lightweight piston (60% lighter) and cap with a larger nipple for bigger house. Also, reduced working volume of air under the cap by some 50%, by blocking off empty space inside piston.
Result is smooth predictable power transition with much faster boost/vacuum transition. No more engine jerking as per above condition.
Some details on Forge Valve Modifications are here. Below are some images.