His highlights, and a few "every play Vs._____ vids". That's not enough?
Not many touchdowns in the Red Zone, so I have to assume he either didn't catch many, or they didn't throw to him there (hence, "no indications").
http://collegefootball.ap.org/article/no-9-clemson-struggling-footballs-red-zone
Someone will say "yeah, they were all 50 yarders", but that's not gonna happen as often in the NFL. In the NFL it's about getting into the Red Zone, and capitalizing. The Bills have moved it all right, they just settled for too many field goals.
I don't doubt he will be a good pro, but I wouldn't give up those picks, in this draft, to get a player like him, for this team.