I also got the ACSS version of the 509 recently. I entered the shipping address wrong and the seller, Freedom Gorilla, made it right for no extra charge, so good on them! My mild astigmatism is playing hell with the chevron-shaped reticle in a way that the Holosun 503 with a similar reticle never did, for whatever reason. It's one of the most diffused red dot reticles that I've yet used, unfortunately. That said, it came with the Glock MOS mounting plate that fit nicely into my slide and, best of all, the optic required no adjustments to be perfectly zeroed at 25 yards! So far, so good, but I've only shot with it once, so it'll be a while before I'm friends with it.