Also like the idea of a vault system, but will rely on thin cover I guess. But a nice feature in terms of aesthetics.
As far as the dreadnought its problems come down to clipping. when it hits a pillar or wall it needs to back up and try again instead of just ramming through it an clipping through a non destroyed object.
I agree, in it's current sate the cover system is kinda optional. I don't feel any benefits for using it, because if there are just a few enemies you don't really need it, if they are in large numbers the cover melts away rather fast.