My $0.02 on Jarryd Hayne:I've been fortunate enough to coach some players who will make the NFL in the not too distant future. They have freakish athleticism (bench 200kg+, squat even more and run a 4.6s 40yd at ~120kg and know all the ins and outs of the game.
Hayne absolutely is a freakish athlete, but his abilities certainly do not stand out compared to what is being produced at a college level here - and I'm not even talking about an SEC powerhouse or Florida State or Oregon; I'm talking about a mid major in a smaller conference - and on top of this, his football IQ is close to zero: he's never ran a route, pass blocked or audibles coverage if he were to play DB. No team is going to sign him as a special teams guy because guys can already do that job and better. He's a waste of a practice squad spot because the amount coaching to get him up to speed isn't worth it.
Kudos to him to have the guts to make his call, and I don't for a second doubt his abilities as an athlete, but the chances of him making a roster and staying on it for very long are in my opinion slim to none.