Very enjoyable
The first 1/4 of the film went by very fast, the plot I mean, but then it held it's ground. All performances were very good. Jim Caviezel's Brooklyn accent (?) was a bit tough to swallow throughout the film.
The back and forth between the two time periods were excellently done. Really smooth.
Jack Shepard's appearance reminded me a bit of Javier Bardem in No Country for Old Men.
SPOILERS
I was surprised that we had a happy ending with no deaths. So many potential problems with plot holes and time travel anomalies, but who does not love a happy ending ?
Really good film.