APB Reloaded's consumable items are a divisive topic. But I think we can all agree that one item has more than it's fair share of problems: Deployable shields.
The starting problem with deployable shields is that you can deploy them instantly, regardless of what you're doing. Losing a gunfight? Deployable shield! Someone get the jump on you? Deployable shield! Jumping through the air? Deployable shield! And, even better, you retain your full jump! The instant activation of the deployable shield is massively exploitable, but that's not all!
In APB Reloaded, crouching and uncrouching doesn't affect your accuracy at all. The only things it really affects are the modifiers you get from some weapons, but the difference is overall minor. Does this matter with deployable shields? You bet it does! An extremely common exploit is to crouch behind a waist high wall (which renders you totally invincible to all damage unless your hitbox is poking out a tiny bit, and even then good luck hitting that tiny hitbox) and then grab everyone's favorite sniper rifle: The HVR 762. With this instant 850 damage you can lock down an area and be totally unassailable due to the fact that you can just line the shot up using the third person camera, aim, uncrouch for only a few moments, take the shot, and then crouch again. Instant 850 damage that the opponent simply cannot contest unless they have the magical ability to predict that you were going to do that and hit you in your 0.02 second window of vulnerability. Which... If someone had that they're probably not going to be playing APB, being honest. How are deployable shields relevant to this? Deployable shields give you a waist high wall anywhere in the game world. This naturally renders exploiting this bundle of mechanics extremely easy.
But wait, there's more! You know what else you can do with a deployable shield? Drop it on an item that you have to pick up. You want to know when this happens? Take and hold missions. You cannot hold anything else while holding a deployable shield and, since most people will still guard the item that needs to be held, a decent team can render an item effectively unreachable to the enemy team by simply dropping it in a corner and then dropping a deployable shield on it. An additional tactic is to drop them at the top or bottom of a ladder in order to block/delay people from climbing it. Though this might've been fixed, I'm not sure.
Overall, Deployable shields are highly exploitable and don't really serve much of a purpose outside of being exploited. I think it's time for them to go.