He's a much better athlete than James Young, and many scouts said he was an elite finisher, maybe the 2nd best in the draft. I don't think he compares to Young at all, other than the bust potential.
While I agree with the boom or bust sentiment, his ceiling is much higher than Turner, imo. I think it was Himmelsbach that said the Celtics think his shot can be corrected and he'll be a 20/ppg scorer.