Objectively speaking Cod is a good series. The budget is always high, game looks good enough, it usually never has problems at launch, there are usually no bugs, it runs at a good fps, and usually the story is decent. The netcode is shit though. The series isn't meant to be realistic either, it's a fast twitch shooter. And Battlefield isn't as realistic as it gets. Go play Arma if you seriously want a realistic shooter.