Regarding the fixed front sight....
I PREFER them if I don't plan on using an optic. I always coupled them with a LMT fixed A2 rear sight. However, I equip all of my social rifles with an optic and UBER PREFER the uncluttered FOV of a flip down front sight.
Today's high end optics are of such quality and durability to actually render flip sights as true "back up" status.
Wouldn't own a rifle without METAL BUIS.