I don't see Winston being worth the pick. Hell I don't think Mariota is worth the pick either but I'd pick him over Winston.
Winston has that Jamarcus vibe that he is going to rely on his natural talent, not put enough work into it and just phone it in. Combined with the off the field stuff I wouldn't touch him. He might of played in a more pro style offense but his play quality has been sporadic to say the least. He's going to get eaten up in the NFL.
Mariota has a ton to learn. They were saying he hasn't had to call a play in the huddle since high school. He has a huge learning curve to over come and then he might get the chance to see if he can handle playing on the field.
Neither of these guys are going to do anything IMO. Teams would be better off filling some other positions and picking up a FA at QB.