Since the original request was for less restriction, I'm not sure I agree with this. Mine might be an exception, but the draw resistance with any of my PVHES (I have 3) is less than with Ed's otherwise excellent offering. Yes, Ed's has notches on the bottom, good for keeping a seal from happening. But that exact same function comes with any stem if you tip or lift it.
However, since the Ed's stem doesn't have the grooves on the side like the PVHES it doesn't offer the same improvements there I think?
If the goal is less draw restriction I'm with the rest, check out PVHES. Maybe even a turbo version if you're really brave?
OF