I love AD, but I'd have to go with Giannis. He can start with the ball and create for himself and others. AD needs someone to get the ball to him. How long were people excusing New Orleans' struggles on bad guard play? You don't have that with Giannis. Then there's the injury concerns.
I will say, AD is probably better paired with a star point guard though. Like if I already have a Kyrie Irving, I'd probably want to pair him with AD over Giannis. But you can't really go wrong with either one.