First, it was sheer pleasure watching Sheen. He's really a fine actor, and this is a nuanced role. His character is a pretty unhappy man (although he doesn't seem to realize it), a very thin-lipped, constrained man. Sheen does a superb job of keeping it subtle in a very affecting way.
The rest of the cast is terrific too, although it almost - almost, mind you - slips over the line of buffoonery and caricature. However, the fine acting and the humor with which the other actors (Debra Kara Unger, Yorick Van Wageningen, James Nesbitt) embody their roles keeps this in check.
The idea of pilgrimage is one that has attracted artists for centuries (remembering trying to get through "Canterbury Tales" in high school English class?), and with good reason. The outward journey - the physical act of getting from one place to another in a rather trying manner - mirrors the inward journey every thoughtful human goes through: how do I get from birth to death in a good way? What does it all mean? How do I become the best person? How do I make up for my faults? How do I deal with the people who annoy me, but I can't seem to shake? How do I journey through life?
I enjoyed the movie. It was well-crafted, beautifully shot and wonderfully performed. I saw it with Tallest Son, who is a skeptic of all things religious, and he enjoyed it as well. If it's playing on the "big screen" near you, go see it. If not, watch for the DVD - you'll definitely want this one in your collection.