I have a DP Pro (triangle/dot) on one AR15 pistol. Works just fine for what I use it for. Batteries last at lease a year left on (it has that feature than turns it off if it doesn't sense movement after a few seconds/minutes). I mounted it out on the handguard rail since that's where it would be on a pistol - out from my eyes vs. up close like on a carbine/rifle. I don't do mag dumps, so none of the heat related issues people speculate about. And, the flip up back up sights look right through the DP Pro if it would fail.
On this 9MM AR15 pistol I have one of those PA advanced red dots. So far, no issues with it. It is supposed to have a 4 or 5 year battery life and uses the same battery we keep around for the DP Pros and my illuminated reticle scopes. Same as the first one, if the sight fails and I pop up the back up sights I look right through the optic. We've decided to replace the Lucid optic on my wife's AR15 carbine with one of these. Like an optic mentioned by a previous poster, the battery in the Lucid goes dead in just a few months sitting in the corner turned OFF. Can't rely on something that hard on batteries.
Good luck, with whichever optic you finally decide on.
