I've had zero problems - Crimson Trace 2 MOA Compact Tactical Red Dot Sight

I have this optic mounted on a 5:56 pistol and absolutely love it. Maybe I just got lucky but it works perfectly for me. Fast target acquisition, clear glass, crisp dot, and great battery life. After 5-600 rds and a few bumps it is still perfectly zeroed and has never come loose. Even after taking it on and off a few times it's still zeroed. Not sure what all the hate is about but I own 2 of these and again have had zero problems with either. Sure there are much better options out there for much more money but I would recommend to anyone looking for a optic in this price range.