Call of Duty: Titanfall
in a lot of ways, many of which i'm sure are more apparent on console where mobility is more restricted and there's auto-aim out the ass, but on PC this isn't the binary first-to-ADS setup CoD is. i'd go as far as to say if you're using anything but a shotgun at mid-to-close range, you're totally fucked against a player with a good handling of vertical movement.
the lesson here is ADS is exposed as a terrible crutch when you give the more dexterity minded players the tools to make the most of their mouse and keyboards, but i'm sure the lesson respawn will take from it is "we should nerf the shotgun".