I think Exum has the potential to surpass Trey at the beginning of next season. He seems to fit Quin's system better as well - he doesn't seem to be too ball dominant, he doesn't mind giving up the rock and runs the floor well. Quin wants players to attack at the 45 and Exum's length is a perfect fit for that if he improves his handle and athleticism. He also has length on defense which is ideal to stop transition baskets as was apparent with that block last night.
Burke on the other hand seems to need the ball in his hands a lot to be effective. His best attribute is shooting a 2 pointer off the dribble and that's a low %, low scoring shot. Seems to me like his shot needs to be "on" all the time to be effective on the floor. I don't think Quin likes that shot. Kinda reminds me of the Johnny Flynn & Minny situation, he was a bad fit on a team trying to run the triangle offense.