she shoved a wine bottle up her coochie!

This was my first Flynn novel, and I enjoyed it! Listened to the audiobook, and I found both narrators very engaging.
The first half of the book, like many people have said, I agree was a little slow, but it gave the reader important character establishment! However, Nick and Amy are rich, good-looking adults with marriage issues, so sometimes this was hard for me to relate to.
But I guess I liked nice guy Nick and found him sympathetic during his parts, and liked silly Amy through her diary entries--I found it easy to "switch sides" on what I thought had actually happened, and I was wondering about Nick's reliability as a narrator.
The second half significantly picked up on the pace and I found Amy to be more interesting.
One of my problems is really a character development/trait issue: I liked Nick and thought I generally understood him in the first half, but all the intense rage and violent urges was a bit surprising for me in the second half. Nick was lazy and pathetic in the beginning, and I don't get why he just 'Yup, I'm going to step up to the plate and make my life miserable for the baby' at the end. Wasn't development, just an about-face.
Amy was interesting in her calculations and reasoning--I had to remind myself that she was crazy, but in a twisted way I could sympathize with her madness. And she was such a patient planner with her lists and crazy amount of research ahead of time that it didn't make sense how she was so stupid to not understand how basic money budgeting worked, and to be so careless as to allow herself to get robbed, and then have to call Desi?? What happened to having so many backup plans?
I think it was also that I liked that they were not likable characters--there is a repugnance aura around each of them that was delicious to read.
And the end was just... I was disappointed but also not. I did not understand why Nick agreed with Amy that he could not leave her, because I felt that Nick was a very normal person and not particularly special. It may have been a little more realistic to not have everything work out the most moral way, and this was both the satisfying and unsatisfying part.
One of my favorite things that Amy talked/ranted about was the women who pretend to be different than who they truly are, mostly to impress others or to gain a man. I feel that this topic was very relatable and true, perhaps not quite to the extent Amy proclaims, but I enjoyed Amy's thoughts on this subject and I think this is a situation that happens frequently in real life.