It flows well.
The characters are all people I'd like to throw under a bus. I've heard it said that it's not the job of an author to create characters you want to be best friends with. Okay, so maybe there are authors who like to explore themes and big ideas, and in doing so create a story with a purpose beyond storytelling. And maybe not all characters should be likable because it won't create any conflict and the story will be kind of flat and boring. However, there are enough unlikable people in the world that I have to spend time with; why would I want to sit down and read a book where almost every main character is so loathsome? I swear, by the end of it I was laughing when something happened to piss Audrey off. I honestly don't understand it. Maybe there are families like that out there. But I don't want to know them.
Still, Heller writes well and these people are well-drawn. I also felt some emotions while reading this book (mainly disgust and annoyance, but also some compassion and empathy).
Also annoying is that the author uses British colloquialisms and slang from her American characters. The story takes place in NYC and the mother in the family is English, so I might be able to believe that the Litvinoffs - the family in question - got those phrases from her. But there are plenty of characters who have never set foot outside NYC who use the same expressions, particularly "meant to" in a way that Americans usually use "had to," "have to" and "gotta" (this isn't a direct quote, because I don't feel like taking the time to look one up, but it would read something like this "She was meant to go to the store for bananas" or "he was meant to clean up his mess"). I don't know if this is the editor's problem or the author's, but it became distracting after a while.
All in all if you have the book and don't mind wasting time with horrible characters/people, go for it. There is something compellingly readable about it. Sort of like watching a movie on Lifetime TV.