My observations from last night:
Negatives: He needs to add a lot of strength. He fell over a lot (got up and back into the play quickly, though) and and lost basically every physical battle (he did compensate for this by effective stick checking, however that won't be enough in the long term). Was a bit uncomfortable with NHL-level speed in the first period, looked better in the last two. Sometimes tried a fancy play, when a simple one would have sufficed(nothing outrageous, though). Also, he needs to work on faceoffs.
Positives: It's uncanny how often loose pucks just seem to find him, speaks to his positioning, which was excellent both offensively and defensively. Effective forechecking and on the boards digging out pucks despite his current physical limitations. His passing was fine, though Drouin had a poor game and trouble finding open space for himself.
In summary a good first game, however I'm still hesitant to keep him in the NHL all season. Clearly has the skills for it, but he really, really needs to build strength and work on faceoffs.