Movies are different from books. Harry Potter and the Order of the Phoenix seems to be the first of the Harry Potter movies to recognize and embrace the differences.
Potter purists will hate it. Things were left out. Things were added. It isn't what Rowling wrote.
No, it isn't, and that's okay. Where the book (the longest of the series so far) rambles across the long expanse of the school year, the movie careens toward its epic climax, feeling shorter than its 138 minute run time.
Movies are different from books. Finally, the Potter movies stand on their own.