I like Baum better as an idea man than as a writer. The characters and lands he created are memorable and worthy of their cultural impact, but things in the story often happen quickly and without explanation. Sometimes explanations are given that don't make sense.
Dorothy is noticeably younger than in the movie version.
It was funny to me how casually violent the book is, except that, when Dorothy kills the Wicked Witch of the West, they explain explicitly through dialogue that it was unintentional.
The movie really tightened up the story and made it better structurally.
I did not think this was an allegory for bimetallism.