What does Bagley do better than Ayton besides getting off the floor quickly?
Just overall looks a step quicker than the competition, which I think bodes well for him. Frequently infiltrates the restricted area to get offensive rebounds and catch lobs even against good, experienced defenders who know what's coming. When guys put a body on him, he still finds a way to get free and make a play. I'd also argue he looks somewhat more comfortable than Ayton taking guys off the dribble.
And of course, a year makes a lot of difference at this stage in a player's development. If Bagley had stayed in high school another year and gone to college next season, he could probably average 25/12. If he's Ayton's equal right now, skill-wise, that really means he's a year ahead of Ayton in his development.