I have to admit, it frightens me a little bit when people start talking about a quarterback's full performance not showing up on the stat sheet. Had we gone straight from Steve McNair to Jake Locker I would not be so afraid. McNair truly did so many things in a game that could not be quantified. We never judged him on pure statistics and that was a correct assessment.
The reason that scares me is because people used that same argument for Vince Young, but it was not the same thing at all. Vince could do somethings with his legs and keep plays alive, but he was never a good quarterback.
Obviously we are all hoping that Locker ends up in the McNair category and not the VY category. The difference, in my mind, is the amount of work they are willing to put in. McNair became a better passer every year while Vince did not. That is the main reason McNair had a long, successful career in the NFL and Vince can't make a roster as a back-up.
Locker has already proven that he is willing to put the work in, so my bet is that he ends up on the good side.