Duncan Jones finds the heart of the Source Code & manages not to lose sight of the emotion in all the action/sci-fi, MacGuffin mumbo jumbo while still resolving & respecting the story line!
 SPOILER 
Towards the last half hour of Source Code, I became bored & felt like it was tedious, but I found myself weepy at the freeze frame shot of all the people laughing & surviving & would like it if that happened for people in WTC. Life!