Having read Wicked: the Life and Times of the Wicked Witch of the West, I've recently been reading Lost (both books by Gregory Maguire). The first (Wicked) was a great novel. The second (Lost) ... well, it sucks.
In the first, you get a very interesting, intriguing character study. Though certainly not the easiest to like person in the world, Elphaba (the witch) is sympathetic and fascinating. I think this is partly due to the novel showing us her life from childhood through to and including adulthood. It also gives us interesting supporting characters that balance off the disagreeable quality of Elphaba.
All of this is missing in Lost where the main character (Winnie) is just disagreeable. And it's relentless. No childhood to help us understand why she is the way she is. Few interesting supporting characters balancing her out. It's just an endless stream of Winnie's smart-ass, defensive cynicism. For example, "She was not very religious, preferring to take her fantasy safely in the pages of books rather than in the uplifting superstitions of ideologues..." The novel is literally crammed with lines like this.
As for the dialogue, most of it seems pointless, as if the Maguire is padding to make a word count quota. The story itself is aimless. It wanders here and there with no sense of having any direction and the sentence structure and word choices seem intended to baffle and obscure. You keep wondering, "What the hell's he trying to say?"
Finally, the endless literary references are tedious. It's nice to know the author is well-read but so are many people. When it comes to a reading, why should we care? Just get on with the story. Maguire ain't no Borges, an author whose references had a purpose. In Lost, they seem intended to simply impress us with the author's erudition. Again, who cares?
As you can see, I'm not particularly thrilled with Lost. Maybe it was written to fulfil some contractual obligation. I don't know. But if you want a good book, this isn't it.
I suggest you read Wicked, and excellent, well-thought out novel that is hugely rewarding.