I've got the Primary Arms 1X prism on the house gun. Why, because the diopter adjustment is nice for my older eyes, and it can run with or without battery power.
MM,
I haven't used the 1x PA, but I really like the 2.5x from PA. I have it mounted on a 16" mid-length gas upper, stainless 7-twist, from PSA. Each time I shoot that configuration, I am super impressed.
I am also a fan of the etched reticle. I can use it as a red dot at close range. I don't think the holdover points are practical or useful, but this carbine isn't used past 200 - 300 yards.
Jason