Honestly, as much as I love BF4, the movement mechanics come close to ruining the game. Jumping accelerates you really fast out of nowhere and you can turn in the air—it's annoying even when I'm the one abusing it to fly around corners. But the real problem is the movement techniques that mess up your hit box and make you harder to hit for no good reason—although I don't know whether those are really mechanics of just niche bugs that will never be fixed.