In a defensive situation sights are unseen
According to all of my previous defensive shooting isntructors, both for CCW classes and for Tactical Shooting classes, ALL have a universal position. In a defensive situation, you WILL become fixated on the target and will NOT even see your sights, ergo, sights are mute. In fact, in my last "Tactical Shooting" class, the instructor drilled us on "Point Shooting", which means:
Point!--Fire!--Scan left--Scan right!
To drive home the point, the instructor took out a roll of black tape. We had to completely tape our sights--front and rear. Yet, we had to maintain about 4 to 5 inch groups at 15 yards and closer. Most of us maintained closer to 2 or 3 inch groups. He taught us, you look at the target, not the sights. To avoid "target fixation", after pointing, we had to scan left, scan right, then fire two rounds. Sometimes firing 3 rounds, sometimes emptying the magazine and reloading.
My point is, we NEVER had the benefit of a sight, fixed or adjustible. Try it sometime. You will impress yourself at how needless sights can become.
Anyone who shoots bow & arrow instictively, knows exactly what I mean.
Doc2005