I use #2, was trained that way, and teach POA/POI is based on proper sight alignment using the top of the front sight for focus. My M&Ps have all shot POA/POI. I have no use for the three-dot system and find it confuses people. My pistols usually don't keep those types of sights for very long. I prefer sights that draw my attention the front sight, i.e. Trijicon HDs, fiber optics, brass bead, single tritium lamp, etc. If a particular pistol shoots low or some other deviation from POA for more than one experienced shooter with more than one ammo brand/configuration, then the sights need some work. I had a conversation with a casual 1911 shooter who had a military/ LE background. He'd gone to the range with two or three 1911s and a .40 Shield. The 1911 groups, he said, were tight. The Shield was all over the place, With his "air gun" he showed me he was still using the teacup hold. I brought him up to speed on the mid-20th Century Modern Texhnique, which he should have been trained on ( he wasn't that old). Then I suggested that he consider that a Shield had a different trigger and was never going to shoot like a 1911. Anyway, he said he shotbit better on his range trip.