I was looking for replacement night sights for my Shield, and was thinking the Trijicon HDs were what I was wanting, but the Ameriglo Pro I DOT looks like the same style sight but not a 3 dot like the HDs, more like a Heinie 8 sight. Ive never heard of them until today. They use Trijicon fronts with different rear sights. Anybody have an opinion on these???