I would not put Leftwitch that high. He needs another year before becoming a top QB. He made a lot of mistakes last year and I think some of that will continue at least through the 1st half of this season. I got him around #15 right now prolly in the top 10 for next year if his progress is good this year.
Actually, I have him that high because I think he'll fall far enough into the draft to have great value. I'm eyeing him as my #2 QB because he has the potential to be a top 10 QB or more this season, and because if he is a bust, he won't have to be taken early enough to kill your team.
I'm sure the mistakes will be there, but they're not going to pull him and I actually like the Jacksonville offense a lot this season.
And it looks like he's a common sleeper pick around these parts, a lot of people are high on him. I know I won't be calling his name too early, but I like the upside way more than a guy like David Carr. (who I also wouldn't mind as a backup)