My opinion, which no one asked for: I think a lot of these red dot responses are to the wrong questions. "Are red dot sights good?" is not the question. "Does the military use them?" is not the question.
Red dot sights are proven to allow a good shooter to acquire a target faster because you're not aligning two sights (front and rear); instead, you're just putting one dot on a target. They also can improve distance shooting for good shooters.
But none of that really applies to the question at hand.
They question was related to a very specific use case: the nightstand gun. That's the bump-in-the-night wake up call. It's dark, you're tired, you're scared, and the situation is unclear. Is there an intruder in the house, or did the dog just knock over the fish tank?
In that scenario, you can rule out distance shooting -- your longest shot is the depth of your biggest room. And fast target acquisition is important, but even if you live alone and don't have a dog, your top priority is target identification, not getting off a quick shot. That's a good way to kill your drunk girlfriend who stumbled into your house. Or your dog, who probably deserves it for knocking over the fish tank.
Your real priorities are (1) your ability to make the gun operational (getting it out of a locked drawer, loading it, etc), (2) target identification, and (3) the reliability and consistency of the gun if you have to pull the trigger. #1 and #2 are not gun-specific in this scenario; they're issues of training for a high-stress situation. #3 is the issue here.
So, does having a red dot sight on your nightstand gun make it more or less reliable and consistent? Well, it's battery operated, so that's one potential point of failure. Subtract a point for reliability (yes, it's unlikely, but the entire scenario is unlikely). But they're illuminated, and if you've practiced with a red dot sight in the dark, it could make you more consistent.
I'd conclude that it's a wash: red dot sights offer no advantage for a nightstand gun.
So it comes down to familiarity: If you train with them, then you should have them on your nightstand gun. If you don't, you definitely don't want them on your nightstand gun.