I watched a few games last night. The biggest weakness would be that he played in a smaller conference, but there is a lot to like to his game.
He's got great hands. Hazel has softer more confident hands than some of the receivers getting 1st/2nd round talk, which allows him to excel at the catch-point in two ways: High-pointing the ball even in with guys draped all over him and catching the ball cleanly, allowing him to quickly turn up field for RAC. He also made some impressive catches along the sideline as well, showing off his body control.
He has a solid build at 6'1 200 pounds, but not an exceptionally strong player in blocking or breaking tackles, but shows some great balance, keeping on his feet through contact allowing him to pick up some YAC.
I really like his quick feet and agility. He makes impressive quick cuts in his route running. It also gives him some slipperiness to his running style. On the tapes I watched, he made some jukes without losing much speed moving downfield that had the DB grasping at air. It's hard to say if he can repeat those actions against superior talent, though.
He's worth a pick in the later rounders of the draft. IMO, his upside would be as a solid, contributing #3 receiver you can depend on to move the chains, but not really a TD scoring machine.