Juliet, Naked was well written, concise, and introspective. However, I never felt 100% invested.
As the reader, I got soooo frusterated with all the characters because they were so complacent with their awful lives. They spend the entire book thinking about how bored they are and how they have wasted their lives, but no one does anything about it. The more they worried about wasting their lives and still stayed in the same terrible situations, I got more and more angry. This was how I felt about Annie and Tucker, but Duncan was a whole other story. Duncan was a wretched human being, and every time the narrative switched to his perspective I cringed. I have had this happen with book characters before (when you are in someone's head with NO filter, it is to be expected), but Duncan could be one of the most cringe-worthy.
When I knew I was getting close to the end, I couldn't believe that Hornby was going to wrap up this story satifactorily, and in some ways I was right. I actually didn't hate the end of the book and what ended up happening with the main characters, but there was an added-on tidbit at the end that didn't jive with what he spent the entire book setting up. I wish it had never been included. It made me re-think the entire purpose of the book (in a negative way).
Even after all that, however, I still liked the book overall. I never put it down, I never wanted to give up, and in the end I wanted to see where it ended. I enjoy the way Hornby writes, and I actually liked Tucker as a character. He was completely flawed and unlikable in many ways, but loveable in others. He was completely honest with himself (and therefore the readers) about his despicableness which somehow almost made it more forgiveable.