I think his playmaking is very good in OZ, the set-ups he does are clearly scoring line quality in NHL. Will he be first on pucks as often, will he have so many broken plays and coverages to exploit in the NHL as he does in juniors? Can he get into and bully his way into thoss prime spots in the NHL as often as now? How is his patience with the puck, possession game? Can he see something is not available, circle the offensive zone or make a play back to the point? Are those passing lanes in OZ he's so adept at exploiting available in the NHL at the same rate? What percentage of those plays are him being a big body that can quickly exploit junior-level breakdowns in defense? Those are my OZ questions. But he's clearly a very high pick based on OZ play.
Then I think an experiment to make would be to place a blanket over the OZ, so every time you see him pass into OZ stop watching. Watch only defensive zone and neutral zone, how many top 5, top 10 plays does he make there? How many will he need to make in the NHL before his OZ game becomes effective?
I'm not saying this as either a negative or positive remark. It's what I've been asking myself when trying to project his game and I think you're going to get a sliding scale of opinions on these questions.