Liked.

Good performance by Jake Gyllenhaal and excellent script.

I appreciated the fact that each Source Code serves for the following Source Codes and from these we get to "get to know" the various people on the train and to establish an ever better relationship with Christina.

Honestly, in my guesses halfway through the film I figured out "where Colter was" but the film still manages to shock with a few twists.
Good ending.