Be sure to ALSO put in a supply of batteries for the sight, and a replacement no-battery scope sight for when the batteries run out.
Excellent suggestion. I also need to get spare batteries for my tactical light on my M+P 9mm.
If I could afford thousand-dollar 4X Trijicon, that would be better, (no batteries), but it's just out of my price range. For less money, I put a Burris on each of my ARs.
At my age with my eyes, a 3X or 4X is ideal. With iron sights I can't make out indistinct targets in brush in low light. With the Burris, the target pops out very clearly.
Up close (zero to about 25 yards) I don't feel I give anything away with a 3X. I've taken high-speed carbine classes and did great in the fast and close drills. But from 50 yards back, the 3X is pure benefit.