As far as we know Mayfield is a harder worker, better leader and more dedicated. It's unlikely he'll be out at the bars blowing lines instead of spending extra time to learn his craft. We knew Manziel had those flaws going in, hence why he fell down to #22 while Mayfield will be most likely be drafted top 5.
His competitive juices may have him living in Florham Park campus. Any conflict he may get on the field, I can see him working harder to improve it the next time. When I think of giving up, I don't think Mayfield.
I don’t think he’ll be as bad as Johnny clipboard but he is gonna be a bust considering what it’s gonna cost to draft him. He’d be great value in the late first early second