I've watched a few Phoenix Suns highlights and games when I was bored and pretty high lol. This is my take from Bender.
1) He needs to bulk up or add more weight. Gets bullied way too easy against stronger opponents, and while he has the foot and lateral speed to keep up with most 4's and even 1-3's, and fits the profile for switch defense to a T. He seems to get lost and not realize he is 7 foot tall. He's agile, more along the lines of quick when switching or rotating back on defense. Problem is, he still far too skinny to guard big men down the post.
2) For a shooter who has shot 37% on 3 attempts, he's already has the great shooting form, and prowess and passing ability to end up as a great above average role player.
3) He has good straight line speed, but he's so atrociously inefficient in every facet of functional areas of athleticism. Terrible stone hands. Couldn't catch at times, fumbled the ball on rebounds, and he just seemed nervous at times when trying to create for himself and others.
4) He has no left hand ability, or dexterity. Meaning he does at time make terrible plays and seem to be unable to use his body control to pivot or change direction. But there is certainly promise, and plenty of potential as he seems to run up and down extremely well.
5) I don't get why he doesn't jump up strong at times. Not explosive, physically weak, and gets blocked by players shorter than him.
6) His defense, and ability to make smart plays/passes tells me that he'll eventually learn how to become a great 3 and D big man. The problem is, for a 4th pick, is he even worth that pick? I would safely say no. Him and Kristap were compared the same, but KP blows him out in literally every statistical category, and is the far more superior player. Dragan needs to add more muscle, improve his court awareness, and just work on being able to create more space. At this point he's a catch and shoot player that can occasionally score on the defense.
He has shown a lot of promise in the 2nd year, dropping 20/5/4 on the Thunder, and scoring 16 right after that game. But in no way, and in no universe is Brown ever going to get traded for him. Brown is clearly the superior prospect and it's not even close.
That being said, I really like Bender. He could fit in our system like a glove, and Stevens could do wonders for his BBIQ. He has shown high levels of intellect, I think it's more along the lines of having competent teammates to pass to, and being able to develop more go to moves or dribble moves or handles. And surprisingly, everyone that has come into the Celtics improve their handles by a little bit. Bender could effectively become a perfect role player. He just needs the right system.