The NEGATIVE aspect of a dead on hold w/ iron sights is that the black front sight is lost against the black bullseye. Rather than stating that the 6 o'clock hold "requires" the exact positioning of the front sight, I would say that the 6 o'clock hold "makes exact positioning of the front sight possible, consistently". In over 50 yrs of handgun shooting, including about 30 in Bullseye competition, I NEVER met a championship caliber shooter who did not utilize a 6 o'clock hold with iron sights. Red Dots and other optics are zeroed dead on, however....