I rented "Facing the Giants" and watched it with my wife and three of my daughters last night. I had heard that it was inspiring but was plagued by bad acting, so I tried to watch it without prejudice.
The acting isn't stellar. In fact, a couple of the actors were quite bad, and several of the story elements were predictable. But those flaws didn't harm my enjoyment of the movie. I found it inspiring and uplifting. I lost a few tears in a couple of scenes and felt a rush of joy at a several others. Overall, it was very satisfying. I would definitely watch it again.
I think the best aspect of the story was the positive message that you can succeed in obeying God and giving Him the glory. He has given us the ability to do all things through His strength, and that truth was powerfully presented. In these days when the church beats down Christians, telling them that they are sinners until they die, it is refreshing to see a movie dispute that lie and give us an uplifting message.