A lot more skill and creativity. Completely different kind of player for the last 50 feet of the ice. Hughes makes some crazy plays in the offensive zone that I've just never seen Mete even attempt.
Small defensemen all sort of have to play their zone the same way. They have to get loose pucks, evade forecheckers and move the puck quickly. To cause turnovers, a smaller defenceman has to rely on a good stick more than a guy like Weber, who can physically dominate most opponents. I have no doubt that Hughes is able to do this against NHL opponents.
Where he gets in trouble sometimes is spurious breakout/blueline/offensive zone plays that cause odd-man situations. I saw it a few times in the shift by shift videos, and a few more times at the world championship. Whether he becomes a PP specialist or a top pairing defenceman will depend on how much of the good he can keep while eliminating the bad.
To offer a comparison with Boqvist, I think I've seen him make a boneheaded play once: I think it was against Frölunda. Attempted breakout pass through 2 Frölunda players, in front of his net.