Don't forget that feats in this edition are used to emulate the abilities of other classes.
I am wondering is these extra attacks makes the Champion subclass of the fighter (with its expanded crit range stating at 3rd level from what I heard) more attractive than the battlemaster one (with maneuvres etc).
In terms of damage, fighters get more attacks but I'm assuming pure barb, pally, rogue will do more raw damage with theirs through rage/smite/sneak. Has anyone run the numbers yet?