I've had a chance to see this movie twice: once in spring of 2003 and once last month. The impact was great both times and i was moved to tears watching it with my family the second time. I think the divergent views I've read here may be indicative of one's world view. Aside for the technical merits (it has been rightfully noted this was a lower budget movie), the themes explored here cut to the core of what it means to be human (pursuing beauty and truth while in a POW camp), what it means to practice forgiveness when revenge is exploding within you, and what it means to love without regard to one's allegiances.
I can see why some would counter that this movie was a cliché playing homage to virtue. But, considering it was a true story, I think it's appropriate to examine oneself against the choices made by these characters and ask what choices we would make. And how do we judge our response? Are we satisfied to dismiss nobility that withstood the crushing blows of torture simply because the "message" is too obvious? Or perhaps it might inspire us to rise above a Rambo-like response when faced with injustice. If we wish to advance our humanity we should strive for, not demean, noble ideals.
Yes, there is an underlying exploration of what it means to show Christ-like love in the face of brutality. What I appreciated is that examination seemed devoid of liberal or conservative manipulation of Christ's message. It simply took a tough teaching like loving one's enemy and showed what that might look like when humans do their best to apply that lesson.