The Order of the Phoenix was, in a word, rubbish.  The acting was definitely questionable, especially during the emotional scenes that our beloved actors have quite got right yet.  The plot was definitely its major problem.  To say it followed the book at all would be a stretch.  A very large stretch.  It is understandable that it would be difficult to include many details in the movie seeing as the book is upwards of 850 pages long.  However, this should not distract from the fact that many of the smaller details are how the story became to be so well known and loved by many.  To me, it seemed as though the director cut out all the little "stuff" and just moved the story from one main point to another main point without supporting it.  One minute, we are watching young Harry and his friends take one of their O.W.L. exams.  The next minute, we are watching he and his gang fly to London to the Ministry of Magic to find Sirius in the Department of Mysteries.  One thing is for certain, the movie was definitely aimed for people that have read the books in the past.  Otherwise, the viewer would have no idea what was going on in the movie, or its importance.  For example, the books depicts many times the fact that Harry is having these dreams about the hallway leading to the Department of Mysteries.  Therefore, he is advised to take Occlumency with Professor Snape.   In the movie, however, we see that he has the dream one, maybe two times before the dream/vision of Arthur Weasley being attacked by a basilisk.  It made no sense at all to leave out these important details.  It also differs from the other movies a great deal.  In the previous movies that we have seen, the entire movie is spent building up to the ending, where there is a final showdown between good and evil.  It is shown in the entire movie leading up to the climax that makes the ending make sens e.  Unfortunately, the Order of the Phoenix just jumps into the ending, leaving the viewer unsure about what is going on and why.  It doesn't make sense to leave out these important points.  As for Kreacher, whom we know J.K. Rowling had leave in because of his importance in the upcoming book, the Deathly Hallows, is hardly shown at all and would have made no difference to the plot that he was taken out as well.  As for other viewers of the movie in the movie theatre, there were definitely much more "ummmm"s  and "what?"s than "oooh"s and "aaaahhhh"s.  Before I end I just want to point out that I am a very dedicated fan of Harry Potter, have read the books at least 5/6 times each if not more, and am addicted to the movie series.  Unfortunately, this part of the series just didn't quite fit in with the level of magic and growth shown in the rest of the series.  All I can say is, of all the movies together, this one is definitely the Squib, lacking in magical skills whatsoever.  And I don't think that a simple Kwikspell course could save it.