Nick is the better player IMO, But, Jack will probably become a player of that standard if he keeps performing like he is now.
But, he kicked 10 goals on Eric Mackenzie and Will Schofield or whoever it was, they are nothing compared to some of the players Nick has to play on and still kicks bags i.e the Scarlett, Fletcher, Glass etc.
Not taking anything away from Jack because he has been in superb form, But, I would take Nick any day of the week, maybe not on the age factor, But, i believe Nick is the better player.