[Mark Henry]

So he's never tried one, has he even had one in his hands?
The only fail mode is wide open.

Think of the valve being like a tiny toilet plunger, with the handle being a solid shaft riding in a brass bushing, so the head (valve) can't cock, it can't go anywhere but in and out. The spring is very light, I'm surprised it can even hold back the oil in the tank. The head is a cone, between the suction of the pump and gravity working on the tank, the valve has no option other than moving open with the flow.
Like I've said, I've seen no hesitation on either my gauge or idiot light since installing my RS valve.

Having to check the engine while running as recommended, tells you that Porsche knew a lot of oil is migrating into the engine sump.
One big bonus of this valve has been the ability to check the oil when the engine is not running.