Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good book, a bit lengthy

A great book, it follows the same basic formula for success that Rowling used in the previous 4 books. However I think you will find that its resolution is not as well defined as in previous books. Its well written and the character development is excellent. Perhaps the only reasons I thought is was unworthy of 5 stars were the tangents the Rowling went on, i.e. Hagrid's trip to the mountains, which I believe sacrificed flow and added unnecessary length to the book.