The difference to me is that Watson has shown that he can throw up big numbers in a game. I expect highs and lows but the highs for trubisky have been nothing you couldn't get from signing someone like Tyrod Taylor or other free agent qb tier acquisitions.
Okay, he can controlt he ball, but he rarely throws over 200 yards and has terrible time finding end zone. Those should be "low" games but instead we say that is a decent game.