I have them on all of my pistols (.22, 9mm, 5.7, 45ACP, & 50 GI). Much faster getting on target in all light conditions. If you have them on your rifles and shotguns like I do, it only makes sense. Your sight picture is the same no matter what platform you are using. I have Trijicon's RMR, Insight's MRDS, Delta Point, Fast Fire, & Docter. I have tried a couple of the cheap knock offs and they work just as well but have lousy battery life. The quality MRD's like the ones I have listed all have battery life of at least 4 years left on 24/7 except the Insight. You do not have to center your sight picture in the middle of the lense like some people say. Just like Aimpoints or EOTech's if you can see a dot anywhere in the lense even if it is in the corners, your POI will strike where your POA is. Anyone who has ever tried my weapons immediately wanted them on theirs.
MadDogDan