Exum to a big extent is still a projection, but what is being projected is extremely tantalizing, I've compared the idea of what he can be to a PG version of Giannis and he's had some intriguing flashes. He has a ton of skill, length, athleticism... but there are things that are stopping him from realizing that ceiling and things he desperately needs to improve(handle) in order to get a chance at stardom.
Before he got injured I thought he was going to push Rubio for his starting spot this year and by the way Rubio was playing and shooting before February I think this was a good bet.
It's a small sample(14 games) to end the season, but his per 36 numbers were extremely promising - 17.5 pp36, 4 rp36, 6.6 ap36 on 57% TS and this is without him shooting particularly well(28% from 3). He had huge FTr and he began attacking the rim this year like we expected him to when he was entering the league. If he stabilizes his handle, iMO you cannot stop him from getting to the rim(or breaking the paint and forcing the help to abandon his man, thus resulting in assists). He's just too quick for most guards in the league.
With all that said, make no mistakes - the Jazz paid for what Exum can be and expect him to be, not for what he is right now.
I'm good with that deal. Hopefully if he breaks out like I expect one of these years he will remember that the Jazz were the team that showed faith in him and stood by him throughout all his injuries.