Weight Savings
One of the biggest benefits of the polymer case is the weight. Even with a larger projectile, the 6.8NGSW is about a third lighter than the 5.56MM. If anything will lead to soldiers liking the round, I would bet on it being this. If you keep the combat loadout the same in terms of rounds, it means a lot less weight banging on your back and knees all day. But, if you need to go into a firefight well prepared, the ability to carry a lot more rounds for the same weight will be much appreciated by those who expect heavy combat. Given the sheer weight of gear that folks often carry into battle now, this is a game-changer.