I really like this one. Baum is sometimes hit-or-miss with how interesting the different kinds of people his characters are constantly meeting are (good sentence, Sho), but he is pretty hit in Dorothy and the Wizard. The Mangaboos, the Valley of Vo, the dragonets, and the gargoyles are all neat, although I wish the dragon herself played a bigger role, and I wish we learned more about how the gargoyles came to be and why they fight and imprison all comers, and what they would have done with our friends when they were prisoners.
Anyway, Baum's weird occasional moments of retro-sexism are back, as when Dorothy, Zeb, and their horse and buggy are falling through an earthquake-created giant chasm in the earth and Dorothy loses consciousness whereas "Zeb, being a boy, did not faint." What? He's a boy, so his brain doesn't have coping mechanisms for shock? I mean, what?
On the other hand, Dorothy is still her bizarrely (and awesomely) unflappable self. Once she regains consciousness, she stares around her at the chasm through which they are still falling, and then she "sighed and commenced to breathe easier." She then proceeds to basically coach Zeb through the whole beginning of the adventure as they approach and explore the land of the Mangaboos, laughing at stuff that frightens him, encouraging him to try walking through the air, and generally sharing intrepidity with all she meets. I particularly like the part where she reassures Zeb that they're not in any danger because they are falling so slowly, he responds by saying "We'll never get home again, though!" and she tells him not to worry about things he can't help. "The boy became silent, having no reply to so sensible a speech." Go, D!
We also have a characteristic Baum-style inconsistency (well, a couple, probably, but one that I particularly noticed). When the Wizard finally meets Ozma, she explains to him that Mombi was her grandfather's jailor and her father's jailor and that when Ozma was born Mombi transformed her into a boy. But in The Land of Oz, Mombi says truthfully that the Wizard brought her baby Ozma and "begged [her] to conceal the child"! I mean, this is a change that makes sense - as it shows the Wizard in a pretty villainous light, and by this point in the series he is really supposed to have grown on us - but it's a pretty dramatic and unacknowledged revision!
Another discrepancy that's actually relevant to the storytelling is that in Ozma of Oz, Dorothy and Ozma agree that Ozma will check on Dorothy every Saturday at a certain time to see if she wants to come to Oz; in Dorothy and the Wizard, Dorothy says that Ozma checks on her every day at four. In which case, why in this book and the next and the next doesn't that ever happen? I think the weekly check-in would explain why they go through so many truly dangerous situations without rescue.
But whatevs! I'm glad for my own sake that they have so many adventures, because I enjoy them so thoroughly!