I work into the night, so night sights on most. I don't have them on my LTT Elites, as they are a matching set of range guns, while my Inox 92 and my Centec, both have night sights.
After trying to order Ameriglo's Spartan's, from their 2017 catalog, after they told me they were ready, I had to make my own. My carry PX4's, (one in nine and one in forty), both have had the rears drilled and vials inserted for reasons. Where back up/training PX4's I have the standard Ameriglo's, just haven't installed them (prefer to train with the same thing, just time issues currently).
Full size PX4 has Trij HD's on it, but it was a good deal and a range gun, that I plan on nightstanding. (may have to change them, but priced right to try)
Fiber optic on my revolver and factory 3 dot on my TZ99, because of lack of options.
CZ's are currently being prepped for mod's (TFO's, Mepro and fiber optic on different ones).
Sig has factory night sights.
EDIT to add, they are on my preferred carry gun, but I consider any gun potentially a carry gun, and certainly a training gun, in case roll around on the floor and grab what is available. (still making sure my carry gun, is and continues to be the right choice)