Uneven, and very much aimed at a pre or young teen audience.  As others have said, some good books and some bad ones.

Interesting to note how clearly Lewis' strong religious convictions come through in the books too.

I agree with Oscar that there wasn't great consistency from book to book, unlike Tolkien. I read these as a pre-teen and some were great stories while others really fell flat.

They vary greatly from book to book, from the really good ones ( I liked The Silver Chair) to the preposterous and or boring, like The Horse and His Boy. Overall, ok but more for 7- 13 year old kids.