Or something alike...? I mean a low-magnification sight where the red dot doesn't obscure the target.
+1 for this. I made a similar suggestion in the sniper forum for a crosshair for extreme ranges that was open on the bottom. At render range a target can literally be thinner than a mildot, and their head can be thinner than a crosshair line. It's annoying when trying to aim and your crosshair/dot covers your target.
For those wondering what OP is talking about: http://images.wikia.com/battlefield/images/e/e0/BF3_M249_Kobra_Sight_View.png