I know many people won't like this review, so I prepare myself at the outset for a barrage of unhelpful votes. I am not planning any major spoilers, but be warned: this review is mainly meant for the consumption of people who've read the book. After all, how many people out there are really planning to base their decision to read this on the opinion of a few internet reviewers?
This book provides pretty much everything we've been promised from the outset: an ending, and a satisfying one at that — but not without its price. Many die, not just the two Rowling mentioned in so many interviews. Many beloved characters die, and some of them die "off screen" as it were, so that we as readers aren't even privy to the details of their deaths, or their final moments of life. Some of these deaths will bring tears to the eyes of any loyal Potter devotee, I've no doubt of that. But as for the main death, the one so many have wondered over? Well, that's where Rowling falls back on a few too-worn literary devices, and where she loses one of her stars.
I found this book to be far too full of easy short cuts and simplistic cliches to give it five stars. Far too many times, Harry and his friends were "mysteriously" saved at the last minute. And the real answers to these so-called mysteries will fall much more easily into the hands of die-hard Potter fanatics who've spent hours studying the books and pouring over the fan sites than they ever do into the hands of the characters themselves. This is too often frustrating. Perhaps it's unfair to criticize or punish Rowling for the perseverance and intelligence of her fans, but the fact is that many of her secrets have been guessed. In fact, the few that haven't seem only to surprise because Rowling conveniently has them pop up for the first time in this book. Magical objects we've seen many times before suddenly have new and useful — and VERY convenient — magical properties. People we've only heard of have convenient new information and relevance to the plot.
She lost the other star because of omissions. Unexplained (and again, very convenient) plot twists, otherwise known as plot holes, are all over the book. A book this long that purports to be the end of an epic series should not have this many plot holes and inexplicable events. (None of which I can go into detail about without giving up major spoilers — sorry.) And most damning of all, when some of the plot holes are explained, it's done in a manner resembling what the brilliant movie "The Incredibles" referred to as "monologuing" — when one character (usually the bad guy) sits around.