Early second round seems reasonable but I could also see him creep into the late first. He has an enticing skillset and so many tools to work with. There are not many 6'5 guys with this kind of mitts and such a sublime passing game. The only weaknesses I could find were his shot which clearly lacks precision and his balance. He is still growing into his body.
While But is more of a finesse player at this stage, Halttunen has the clear profile as a power forward, often playing with brute force. His shot is better than But's for sure, and he is a fine prospect, but I don't like his Hockey IQ.