I'm comfortable with the M16A1. First issued rifle. Later my issued rifle was the M16A2 for years. My last rifle was the M4 Carbine with all kind's of gizmos issued in a really hot place. So I just inherited an AR15 from my elder brother. It's a slick side, no forward assist, with A2 furniture on it. I see no need to change it. Seeing as I installed a nice ambidextrous safety lever.