I'm one of the bigger Narnia fans around. I loved the books as a kid,a nd have reread them several times as an adult.
Caspian, as a book, to me is not good movie material. The movie differed in several areas from the book, but kept most of the important (to me) stuff in it.
As a movie I liked it. Not as much as the Lion the Witch and the Wardrobe; but I doubt any Narnia movie can touch that one story wise (except, maybe, Dawn Treader)
I think I simply am too emotionally invested in the books to give an objective review of the movie. My oldest boy loved it. He is 10. Maybe that's the target audience.....
Ripicheep was great; Peter and Caspian interrelationship were not as good in the movie as was the book; the professor didn't get enough development.
All that said, I'm going to buy the DVD when it comes out. I doubt I'll see it again in the theater. If I had to compare it with another movie, I'd put it up there with the Third Harry Potter movie. A decent movie, but lacking from what the original was