Got a Red Dot sight for my M4 back in March mounted it, and zeroed it. I thought this was gonna be a good deal, until I tried it on a milk jug a 100 yards. No precision, it almost completely covered the jug at that range. SO!
I put the Leupold 2X7 back on, re-zeroed it for 225 yards, and put a barrel mount on for the laser sight, and zeroed it at 50 yards. I have shot the M4 so many years with a 2 power Leupold on it, I doubt the red dot was that much faster anyway, if at all, and the laser is for night time varmints that try to double team my Jack Russell. And two legged varmints as well. I also think it could be useful if a coyote comes from the wrong direction and gets in close before I see him, and maybe hogs in the creek bottoms. Either way it has a pressure switch, and I mounted it directly in front of the front sight, so it ain't in the way.
The red dot on my Buckmark is a dream for squirrel and night time cats and skunks. That one I like with range being considerably closer. Heck, I may put the other red dot on my squirrel rifle.