Watching Son of God is a bit like listening to a pretty good tribute band doing a set list of Top 40 hits you have heard most of your life. The delivery is not bad, and the individual songs carry enough significance for you (both emotional and biographical) that the performance really only needs to remind you of what you already love.
If that comparison feels glib, then watching Son of God could be compared to watching someone else's professionally filmed wedding video. You understand why it is so precious to the person sharing it with you. But it is a summary of what happened, not a re-creation of the event. Plus you risk offending your hosts if you mention that one of the bridesmaids is wearing slightly different-colored shoes, or that the organist is playing a different song than what was listed in the program they showed you.
What I mean to say is that watching Son of God was not a dreadful experience, but it wasn't a particularly inspirational or entertaining one, either. We can excuse the latter fact on the grounds that in spite of its packaging, the gospel narrative isn't meant to be a vehicle for entertainment. The former is more about the medium than the message.
Marshall McLuhan is credited with coining the axiom that the medium is the message in his book Understanding Media: The Extensions of Man. Two decades later, Neil Postman pithily expressed an important related thought: religion, he opined, rarely broadcasts well, because it is impossible to sanctify a television set.
Postman's conclusion may be slightly less inescapable in an age of DVDs and streaming video. Today, we have more access to a variety of content, and more control over how much of it appears on our TVs.
But the movie theater is a different story. As independent theaters gradually go out of business, there has come to be, if anything, less diversity at the movies. Theaters try to keep money flowing by investing in IMAX screens and 3D projectors to justify raising prices. Going to the movies is an event, an excursion, and the "go big or go home" insistence on spectacle is the creed of the movie theater.
That's important when we're considering both how Son of God works and how it doesn't. Son of God is edited from footage already broadcast on television (with the addition of some deleted scenes). So it seems evident that it is concerned with giving Christians an excuse rather than a reason to go to the theater. (Many of the Christians who go to see the film will have not only seen this story before, but they will have seen this footage before.)
When a narrative film (say, the Lord of the Rings trilogy) releases a director's cut or a DVD with extended footage, the goal is to add value so the viewer will be prompted to buy something he's already seen. Or we buy the DVD or digital film to own what we have already experienced, so we can watch it (and relive the experience) any time. But in the case of Son of God, viewers may already have the DVDs—so what they are really purchasing is an experience in a theater.
So to review Son of God requires as much commentary on the experience theatergoers are buying as the film itself. And here again, the ability to buy DVDs and digital downloads of films has radically changed the reasons that we still think of theatrical screenings as important.