I really enjoyed this book. I felt that it was a break between the action of the fourth book and the action of the seventh, revving slowing up through the fifth and sixth. This installment takes the time to focus on the characters as they face one of the toughest challenges of being teenagers: complete and utter disillusionment.
Gone is the at-least-outwardly-cheerful world of the first, second, third, and fourth books. In this one, the government is blatantly corrupt, the adults are all distant, preoccupied, and deliberately hiding information from you, everyone seems to hate you, no one seems to care about your problems, and you are on your own.
Harry deals with the large problems — the verbal and physical abuse by an authority figure comes to mind — and with the smaller problems, such as jealousy, competition, lack of acceptance, and suspicion from his peers. He deals with feeling abandoned by his mentor and by his community. And he deals very obviously with a serious case of Post Traumatic Stress Disorder. Relationships are at the forefront here. So is the theme of duty.
War is hell, and this book takes the pains to blend the realities of growing up with the gathering storm of the coming battles. The book is a slow read, but I felt that having this lull in the action really made the upcoming books meaningful. You got to know the characters here. You learned to really care.