Fiber optic sights are good for tactical target shooting. Bad if you intend to be in dark rooms without a light source. In pitch black you won't be able to see your FO's. But if you are anywhere you need night sights it might be prudent to have a weapon light of some kind. I keep thinking about our low light scenario shoot this last league. Night sights were a must if no flashlight was available, but even then a flashlight (weapon mounted even better) without night sights may have been a better choice. Try it in a realistic scenario where you have enough light to identify your target and see if you can't pick up those sights.
9mm vs 45 ACP? The answer is 42.