In Call of Duty Advanced Warfare, you can't shoot at enemies while you're sprinting forward or while you're underwater. Black Ops 3 changes this.
In Black Ops 3, you can shoot while you're sprinting at enemies. The gun never goes down and it's something that we came to appreciate during our time with the beta. It's constant action and you're never caught with your hands down.
There is also the potential for intense underwater gun fights. There were times when we and several teammates faced off against enemies in the water. It also makes the water a much better hiding spot because you're not as vulnerable.