Honestly my only problem (and I know it has been fleshed out before) is the rebounding concerns. As somebody pointed out in the youtube thread, while he went 11-15, he also only had 1 rebound.
But yea, he is a roll threat, has good athleticism for his size, moves very well, and is a good leaper in space. That poster on kevin, showed off another part of his game. The constant threat of him stroking it from deep keeps the bigs on their toes, in a way that lets him put it on the deck and take it to the rack.
Defensively he is very intelligent. He seems capable of sticking with his man, and his decent length allows him to alter shots at the rim. As pho pointed out, he stayed with kyrie, and blocked his layup, no easy feat for a defender, let alone a PF/C.
He just makes the Celtics so much more versatile.