I thought Emmet was awesome, and Jeremey's depression & anxiety felt believable too - particularly how there was no magic fix for it. I didn't find him annoying like some others have mentioned, because he honestly couldn't help being so down all the time.
It is a very character driven book, which I usually like - I do not need lots of fancy shit happening to characters as long as there is some sort of development. Unfortunately, I found that both MCs lost their momentum once they were living at Roosevelt. And because the book is all about the characters, the overall impression for me was a little dull and a little flat. Once the MCs lost their oomph, the book did too, and it kinda just quietly petered out.