Wasn't there speculation or something that the soldier could get an ability ti give out incendiary ammo? That would be like a damage boost and it would help the team and probably give more XP.
They mentioned the Soldier was giving out Armour Piercing rounds in one video, and said it gave a damage boost - I've heard about the incendiary ammo as well, and from reliable sources, but there hasn't been official mention of different ammo types anytime recently, so I won't say 100% that they're still in.
Hope so though.