Night sights are about as useful as rear sights with a ledge for racking one handed for when your other hand is injured. The chances of you having to use your gun is very slim, and the chances of you having to rack your slide for whatever reason while missing a hand is even slimmer. Night sights can give an edge but it's another one of those weigh the risk vs cost issues. I think a weapon mounted light is essential. I don't trust a handheld as you'll be firing one handed. If the argument for that is not pointing your gun at something to illuminate it, I think that if there's someone in my house who isn't supposed to be there, I'm not going to be polite.