Ace has certainly played some really promising games and he seems like a good kid.
It's just hard to see what his main NBA skill is. In this respect he differs from everyone else in the Top 10 of his draft. The outside shooting has come and gone (his 3pt % is worse than league average at the moment), he doesn't get to the basket (or FT line), he struggles finishing through contact and he can't get separation against defenders.
Ace's "comfort zone" shot is still the same as in college – the (very) long pull-up two. Not a great shot in the NBA. He's generally been at his best playing off ball, mostly ignored by defenses, roaming the baseline for putbacks and alley-oops. That's fine at this point, but obviously not the type of thing he was drafted for. Time will tell how he manages to broaden his skill set.
People keep saying that Ace needs to bulk up for next season, and obviously adding strength will help, but IMO his main focus should be on ballhandling. He's a talented passer, but he needs a lot more confidence in his dribbling to make full use of that skill.