Im not a fan of the special attacks to begin with. But I understand how they want to add some flavour to combat. An complaint I often see on the internet is that weapons feel to bland and lack their own identity. But tbh no player that I DM for or play with voices this complaint. Its only a thing I see on the internet. At the table people are supposed to use their inmagination so I think its an...interesting take. That said I can understand that Larian isent bringing out a pnp rpg but a video game and they need to hold peoples attention I suppose. Giving weapons something more then stat changes or visual changes is probably better for the game in the long run as it allows the devs to implement more unique and special weapons as rewards.
Balancewise I feel it infringes a little bit to much on the Battlemaster's area of expertise. Their whole sthtick is that they can perform special attacks and control the battlefield via their actions. Things like a cleaving attack actually ARE a battlemaster move and I feel giving that to everyone without compensating for that somehow nerfs the Battlemaster. Maybe allow them to make special weapon attacks twice per short rest or something like that? That would stay in touch with the archtype of the class, keep the special moves in the game; and still make the battlemaster destinct from other classes.
The bonus to attack a prone enemy in melee is advantage on your (melee) attack. And that is insanely powerfull if you use things like great weapon master for that +10 damage. With the advantage your odds of attack increase alot and if you hit the damage is huge!
