I don't like Manziel though I can't deny he's got insane skills when everything falls apart. I just don't believe that will serve him well in the NFL where everyone is fast and offenses are all trying to keep things under control during possessions. The first time things fall apart he'll whip out his "Johnny Football Magic Bag of Tricks" and surprise someone. Aggies everywhere will say "I told you so!". A few weeks later he'll be utterly destroyed by some DC who understands how to stop him. Shortly after that everyone in the league will have seen how to do it and Manziel becomes a footnote in some teams draft history with a note scribbled next to it reading "Should have known better".
One guy making **** up on the fly doesn't win NFL games for very long. A few weeks, maybe a season if he's on a team with some assets. It ends the same way though. Picks and injuries followed by "I hope you invested that rookie contract money wisely"
A wise man once said "...well at this point it's all been hashed out and you either see it or don't. Hoping for a win next week" - HTown2ATX