OK, I finally watched a Watkins highlight reel. This did nothing to dispel what I've read about him.
He caught 2 balls on what were basically "go" routes.
All other catches were at/behind the LOS.
He carried the ball a bunch of times. Personally I don't want my #1 WR exposed to the pounding that NFL DE's and LB's will give him if he's handed the ball. Maybe you give him the ball 3-4 times in a season just to keep the opposing defense on its toes, but, I would not mind one little bit if he never carried the ball (on a hand off) for Buffalo.
He does snatch the ball out of the air beautifully, but, he will not "make a living" in the NFL on receptions at/behind the LOS.
He looks like he's a willing & decent blocker based on that game.