A good movie, not great but worth seeing. It's one of those movies you need to discus with your friends to determine how you really felt about it.
Some parts are predictable but overall it's a fresh take on the "if I could turn back time" theory. I did find it satisfying that all my perceived 'plot flaws' were resolved.
Of course there's Jake and my second biggest complaint - no shirtless Jake. My biggest complaint is not Source Code but the preview for The Beaver - staring Jodi Foster and Mel Gibson as South Park's Mr. Garrison only with a beaver.