I have two bad shotgun habits, picking up the sight with my opposite eye and lifting my head during my swing. This sight helps with both issues. You can't see the dot with your cross eye, and you lose sight of the dot if you move your head. It is also much easier to see your lead on a bird, because you can always see the dot.
Pros: Eliminates the tendency to pick up the sight with the opposite eye and forces better shooting form
Cons: rigid platistic cover, some modification required to to the stock is required to mount
This review was written in the old system and had content requirements that are different than reviews written today.