Actually, I have to say that I prefer #1, if I understand correctly.
I haven't used suchey & earl's marines, or played COD. But I have played some games where the iron sights create a very small "hole" to look thru on the screen, which I assume is what you mean. I don't like it, because when I shoot, I put my eye real close to the rear sight apature, which makes the "hole" look bigger, like BIS's sights.
I also prefer the black, fuzzy picture of BIS's iron sights over some much more detailed and focused sights I've seen. When you are aiming down the sight, obviously the rear sight isn't in focus (because you are focusing on the front sight tip). So having ultra detailed and focused sights is just too unrealistic for me.