From the tweets and videos I have seen Blackwell has a longer Wingspan, better vert, maybe a better on ball defender, very explosive off the dribble and bounce, and is more athletic. Dubar looks like a very good 3 level scorer and can really shoot the 3, he can really pass the ball, and has good court vision. Dubar is 1 inch shorter and looks to be more crafty in the way he can score the ball, and can defend well too. Blackwell can get to the rack anytime he wants. Both look like good shot blockers, and are very long. I would say if we were to categorize each at an actual position I would say Dubar is more of a CG/SG while Blackwell is more of a SF.