I have a Viper PST 1-4, it works just fine.

If I'm buying another for a hunting AR, I'm looking hard at a VXR with FD duplex. I have one of those in 3-9, and like it. Good glass and useful with or without the illum on.

My thought is how much glass do you really need in a 1-4 optic? I'd probably be looking save the VX6 money for something else, and go VXR. On the other hand, the VX6 is 1-6, which is a nice mag range that you could do nearly anything with. Twice the money though..

Another option, if you aren't dead set on 1X on bottom end, is VXR 2-7. Same money as the 1-4, but I would think the 33mm obj would help with low light some over the 20mm.