I agree that this book was quite the feat to tackle for the cinema. With that said, there were so many things left out and other items that too much time was spent on (i.e., all of the 'Won Won' stuff)...could have easily cut that time in half, added in some other very important, key items from the book.
Also, not ONE fan of these movies & books would have complained had it been 3 hours in length. An extra 30 minutes could have done wonders for the Half-Blood Prince.
Now we all must wait for both The Death Hallow movies to rekindle our sincere affections for these adaptations to a wonderful series.