in the field? ditto dust, or salt water residues, or mud, or ice, in the dark, with hostiles all around?
There's a reason why military rifles are built the way that they are, you know. Luminous sights on a lever action are a $200+ custom smithing job, not a drop in $100 thing like they are with an AR. It IS dark half of the time, ya know, and such sights are a HUGE help at hitting. they give you about 3x the effective range that you'd have with out them.