I've done my fair share of shooting in the dark and here's what I've learned...
A Tritium frt sight way down on the end of an AR15/M16 is all but worthless in high stress, heat of the moment engagement. It's mildly usable in a stable fixed shooting position when you can focus on the itty-bitty spec of trit light.
A fixed 1X or 2x "shake awake" optic will run circles around night sights, esp in high stress moving target situations.
Very very hard to beat the built like a tank Primary Arms 1X Cyclops or the 3X Raptor ACSS series prism optics plus they have adj diopters for aging eyes! Catch 'em on sale during a holiday and you won't believe how you lived without 'em. I've got them on everything from ARs to AKs to HKs. (Mrgunsngear sometimes has a code for a free Anti Reflection Device for the front of them)
YMMV,
White Rabbit