Bender is a high risk pick: I don't want the Celtics to pick him. He reminds me of Kwame Brown: big, fluid, tons of talent: but talent is not enough (see Jeff Green). The best players are the nearly insanely competitive players with talent (see Kevin Garnett). For example also, Al Jefferson, who is a good player used to score 40 - 50 points a game in high school. People said, its only high school. But if Bender hasn't used his height and talent to score more than 4 points per game, how can you know he has the character to do it.
I think that for their draft picks, the Celtics like to see production. KO is enough skinny power forward for one team. Celtics need some power up front.