He has elite length and some position versatility (if he can put on some weight), which the NBA loves. Defends pretty well and can tip balls in the passing lanes. Also, he's not a shot hunter, which is probably a good thing. More of a facilitator. Runs the break extremely well. But, you can probably count on one hand the times that he created his own shot last year. And, with that release, he would get a lot of shots put back in his face in the NBA.
If he's still in the first round projections next spring, then he (and ISU) have had a good year. And that he really worked on the holes in his game. I'm all for him having a tough decision to make next May. But TH is also one that I don't think would jump for the sake of jumping. I think that he's going to need to be a pretty sure first rounder to actually go.