I've recently done side by sides of an SWFA 6x, 3-9 (HD) and a VX2 3-9. The VX2 and 6X are about the same to my eyes. Any difference will be in the reticle, not the clarity or light transmission of the glass. The SWFA 3-9 with HD is a tiny step up. Honestly though, I can't imagine a scenario where the outcome of a hunt would be any different for any of them. When it gets REALLY dark (heavy overcast and rain right at 30min after sunset) the very dark lines in the SWFA reticle are better than the duplex in my opinion.
