I see his upside as Joe Flacco lite. Not only b/c they're both tall, lanky and awkward with big noses. Mostly b/c of their game.
Comparing him to college Flacco, they both seem to use their height well, and pick apart the defense with short and intermediate routes. Both capable of throwing the deep ball, but hesitant to. He could be Flacco, but won't have Baltimore's defense to lean on, so he won't have near the immediate success.
Even if he becomes Flacco, he certainly wouldn't be worth the #1 overall.