The biggest problem with the damage model right now is the unarmored target. I did some test with bots (most of them don't have armor), and found out that unlike INS2, unarmored target still requires 2 shots from 5.56 to take out (on the chest). Since the removal of AP ammo is to make armor more useful, I'm fine with it, but I also hope there will be a significant difference between Heavy Armor/Light Armor/No armor in the future.
For instance, unarmored target should always be 1 hit kill on the chest, but it gives you big advantages in running speed/stamina/ads speed, which are somethings the game is lacking right now. With heavy armor, the current damage model is actually ok, but it needs more penalty in mobility. Thanks.