I think this book was written to be a movie, and it will be a movie pretty soon, starring Anne Hathaway. It's incredibly unsubtle with the gender and cultural critiques. The prose is occasionally clunky and never all that memorable.
But, heck, it's a perfect hook of a plot, totally entertaining, and the resolution of the mystery/suspense subplot was clever and took me by surprise (no spoilers). I think if you come to this book looking for a smart satire, you're going to be disappointed: it just isn't that deep. And, I'd argue that the subject matter isn't really that deep either: a lot of reviewers focus on the vague Christianity of the protagonist, but isn't Evangelical Protestantism often just like that?
Come in with low expectations and enjoy it as a romp that manages to take the piss out of men, women, Christianity, motherhood, right-wing politics, crunchy granola culture, etc. Or wait for the movie if you want basically the same experience.