It's mostly easy to get invested in the story and the characters, although there were some moments that made me go "wait, what?" I can't quite decide if Katniss is just too up in her head to notice people trying to help her, or if she's too paranoid to believe they are, I'm leaning towards the first.
I saw someone else comment that this book had "the worst cliffhanger." I'm not saying I foresaw every detail of the ending, but the main of it was totally predictable, so I'm asking "where's this cliffhanger you're talking about?"
I'm a bit unsure about the rating, I've had a hard time putting it down so I could try to sleep, but this might be more because most of the chapters ends with something happening so you have to keep reading to find out, as a reader I would like a book to have more opportunities to take a break.
EDIT: After mulling it over a bit I decided to up the rating.