The knock on him has alway been that he runs a very limited route tree, has straight line speed but poor change of direction ability. When I say pass catcher, I mean the quality of being a pass catcher. It did seem like when he got to Jags, Pederson used him more successfully but there were a lot of manufactured touches at or behind the line of scrimmage (the 114 season had some crazy number behind line of scrimmage) where they just tried to let him use his speed to make up for not being a very good route runner. He could run seems and go's and crossers but not a ton more. The jags had to tailor the offense to him somewhat. You can't go around tailoring your offense to a just okay player but when you do, they'll get those numbers.
Had an issue with drops, that may be gone now, this one I don't know.
And I know you didn't mention it, but he can't block for sh*t.
That being said, is anyone out there at TE in FA? If you don't mind the not blocking, not being able to play inline and are willing to tilt your offense to what he does without hampering the rest of your pass catchers, he's worth a contract.