I loved it! It was clear to me that JK Rowling herself has created the idea, because the plot fit in very logically with the rest of the series. It was really fun to catch a glimpse of our old favourite characters (answering the question of Where are they now?). The evolution of the characters and the wizarding world was very believable, with relation to the previous seven books. This book is quite different in style from the rest of the series, which I think was important. It is not the eighth Harry Potter novel-- I see it as more of a bonus add-on, which is emphasized by the fact that it's a play script rather than prose. It's a very quick action-packed read; it took me only about 3 hours to finish. This makes sense since it is written for the stage, and I can't imagine the performance would last more than a few hours. I think if you go into this book with a background of what happened in the original series, knowing that this book is going to be quite different in style, I think HP fans can enjoy this book as much as I did. I look forward to re-reading this one!