As noted, pistols for self-defense are generally set up for zero (dead-center) sighting. For bullseye shooting, it is much more consistent and accurate to aim at the 6:00 point, assuming the targets are the same size and distance. If you want a 6:00 hold with an SD pistol, you'll probably need to change the front sight height a couple of sizes.

I find it very hard to see black sights against the center of a dark or black target. A red insert is not much better. You would have the same problem in poor light in an SD situation. For SD, a three white dot system is a minimum requirement. A three dot tritium system is even better, and works equally well in near total darkness and daylight.

I've just installed a gold bead on a revolver intended for woods and hiking use. It promises to be very effective when there's any sort of top or side light. For pistols, I'll stick with tritium sights, but options for revolvers are limited. Fiber optic sights seem a little too trendy and fragile, but that's just me.