By far the biggest knock on Zacha, in my opinion, is that if a 6'3", 210# kid that can skate like the wind isn't blowing away Junior competition, how much of a ceiling can there realistically be? How much leeway do you give him for any of the numerous adjustments he had to make in playing his first hockey season in North America?
EDIT: HOOOOOOOLY **** are those U-18 goals impressive though... Absolutely owned the neutral zone and made goals from nothing basically by himself. The goal at 3:15 was just insane, even if it was against Latvia. That ability to identify space, and then use his speed and hands to attack it with control, that's what you want in your best players.
Man, I'm glad it's not me making the choice at #6. Still no idea how to choose between Zacha and Barzal, let alone all the other strong prospects likely available at that spot.