I'm kinda hoping for some kind of a knockdown effect mechanic to armored but light enemies where they might still get up after a shot to the noggin' but not zeroed because of some implants. That would be cool.
I have seen this kind of mechanic in the same type of games that have a 'buff' for headshots.
Particular weapons, like say shotguns at close range or heavy rifle shots, will cause an opponent to stagger. Which can open them up for a follow up, for example. Also things like enemies with a ballistic style riot shield where you can try to shoot through the vision slot or my favourite, a shot to the ankle or briefly exposed knee that then causes the enemy to stumble and have to move the shield away from the optimal angle in order to correct their balance.