Reminds me of my reaction to "Raiders of the Lost Arc", a movie I didn't like at all. The larger reasons I didn't like that aren't relevant, but one of the most annoying things about it was that every line in the movie had been parodied to death such that the delivery of the lines in the parodies was better than they were in the inceptive movie. With "The Wonderful Wizard of Oz", this is also true... but the lines were way better in the film adaptation, which is incredible. There are certain creative flourishes here and there in the book that couldn't have made it into the film, but the overall package can't help but pale in comparison to its essentially perfect adaptation. So it's a bit underwhelming, but still quite nice.