Comparatively, both are good, thanks to the randomness of the dice roll. AC, Advantage, Disadvantage, etc.
In longer, tougher fights though, I'd say champion deals more damage more conscistently, mainly because the don't spend superiority dices dealing damage. Champions are mainly damage focused. Battlemaster grant bonuses to the damage they do. In quicker fights, battlemaster. Longer ones, champion.
In longer, tougher fights though, I'd say champion deals more damage more conscistently, mainly because the don't spend superiority dices dealing damage. Champions are mainly damage focused. Battlemaster grant bonuses to the damage they do. In quicker fights, battlemaster. Longer ones, champion.