Hi,   
after fiddling with it for a while, I found the "Realistic ASP IR A-A Missile Recticle" option to have no effect anymore. I have tried following situations, all with it enabled in my own game settings:   
-MP Server hosted by someone else 
-MP Server hosted by me, with a mission made by myself 
-MP Server hosted by me, with a mission made by someone else 
-MP Server hosted by me, with a mission made by someone else, but with me resaving the mission 
-Offline with a mission made by myself 
-Offline with a standard mission   
This very much is a realism killer.