I also agree with you guys, i play airsoft alot witch are weapon replicas and you only really see the front and rear sights witch make the 2D Iron sight realistic, but what would be cool is to make it look like your really aiming down the gun instead of just an iron sight picture.
BF2 looks like it can handle it, I must agree that using the actual gun modle would be better. It adds to the imersion and is more realistic than the ones drawn in photoshop, no matter how good they are.