Thoroughly impressed with this optic for the money spent.  Got out to the range today with my new AR10A4CBF, put about 60 rounds through it.  Only took about 5 shots to get it zeroed at the 25m target.  Shot mostly at the 50m, and did a few at the 100.  Was hitting dead on at the 50 mark, and was hitting about 3" high at the 100, not bad at all for a 1x RDS.  Held zero just fine even with the .308 recoil.  

Only problem I was having was the base screw coming loose, once you get it set where you want it, I suggest using loctite or some type of thread sealer to keep it from working loose.  I tightened it quite a bit with a crescent and it would still come loose, didn't want to go TOO tight for fear of stripping the screw out.

I'd recommend this sight to anyone looking for something in the $100 range.  Also like the fact it takes one AA battery, cheap and easy to get a hold of.  Well, that's my report on the PA M4 clone, hope someone finds it useful in their search on optics before purchasing.

Oh and just FYI, a quarter works perfect for adjusting the windage/elevation, I keep one in my range bag, comes in handy for a lot of things.