Casey's mental game hasn't been NFL-ready so far. He's been streaky and quick to get bummed out and flukey when his supporting-cast makes his job hard.
I wasn't surprised when he didn't get chosen in the first 5 rounds because I think he is a diamond-in-the-rough, though, at first, I was surprised he hadn't gone by the 7th round for the same reason.
Then I looked at the large number of QBs this year that were NFL-ready, and combined it with the small number of NFL-QB jobs up for grabs.
At this point, I can't help thinking that Casey is lucky he gets to go the Free Agent route. If he was tied-into a team by the late-draft, his chances of finding the team best prepared to train him into NFL material OR pay him what he's actually worth would be pretty slim. This way, Casey has more control, and while he might make less money in the short term, if he's as good as we think then he'll be able to shop up his price and choose his ideal team faster over the long-term too.