[Billthedrill]

I have both with the red dot co-witnessed to the iron sights, and zeroed at 100 yards.

Second the motion. It isn't difficult. Also, spare batteries. I also have more than one spare magazine... ;-)

[Cobra64]

My rule of thumb is 8 magazines per firearm. I train a lot and cycle through 5 mags in a class. The remaining three are for serious work.