I personally wouldn't pick him with our pick due to his issues. There is no doubt the talent is there, and without the character/attitude issues he is likely a top 5 pick in the draft. He is bad defender at this point, but I think that is attributed to his attitude. I think he has the capability to clean the D-end play up if he wants to.
Even though I personally wouldn't take the chance on him with our 1st, I trust that Dubas and our staff have done their due diligence, and will give them the benefit of the doubt if they pick him, and that they strongly feel as though they can clean him up in terms of character/attitude and his defensive game.
I do have a feeling that if they are on the board at #25 (barring a big slide of a high ranked player) that Leafs will pick either Miller or Merkley.