I watched a few videos of Matthews on YouTube. Not the highlights, but the full game tape against SEC competition.
That guy has it. He is willing to block, runs great routes, and aside from a few drops, he has some crazy potential. He's not going to light it up with speed, but I don't really think we need that. He can go up and make a catch, and his game speed is fast enough where he can get plenty of YAC. Just watch the videos of him against both South Carolina and Florida (2012, couldn't find any from 2013). Just watching those videos passes the eye test with flying colors.
I watched some similar videos of Robinson and Lee, against worst competition. I didn't come away very impressed.