I know this thread is old, but I thought I would/should give an update.
So far, after two seasons, the sight is holding up well. After taking the sight off to clean my shotgun after last season, as well as taking it off to wrap my shotgun this year, it was still dead on when I went to the range a couple weeks ago. I have not had any issues with it snagging on anything and it has not gotten knocked out of sight by setting my gun down.
Overall, I have zero complaints about this sight. I toyed with the idea of putting regular rifle sights on my gun, but this sight gives an extremely clear picture when holding on a bird.
I would highly recommend this sight.