I never said or was thinking about going on a rant bout how "realistic" it is because like you said its a video game, but what I will say and this is just opinion is that I find BF3 has more variety. You can be infantry, air support, drive a tank and even a boat or jeep. COD which I played for long enough I just get bored once I max out my snipers, got diamond camo and its just boring.