OK, but I think for fans only

Rating: 6/10 (13 August 2007)

"Harry Potter and the Chamber of Secrets" is, unfortunately, not one of the best Harry Potter movies despite (or perhaps because of) sticking relatively closely to J.K. Rowling's original novel (IMHO one of the better in the series). Some parts feel overlong and others too short, and there are signs that director Chris Columbus was growing fatigued in his second (and final) entry in the series.
Overall I think we have a good fantasy film here. Other than Rupert Grint's Ron (Grint's whole range of facial expressions seem to consist of scrunching up his face in a Spielbergian "ewwwww" pose) the young actors were growing well into their roles, and the new adult performers are excellent. Kenneth Branagh is well-cast as the pompous celebrity wizard Guilderoy Lockhart, hired as the kids' second "Defense Against the Dark Arts" professor. The particular standout here is new cast member Jason Isaacs, who is the very image of petty evil as Lucius, the father of Potter's nemesis Draco Malfoy. Some parents might feel Lucius' treatment of servant, the house-elf Dobby, is overly harsh but it introduces an important theme for the series. Contrary to what I'm tempted to think the film producers would like, "Harry Potter" isn't just an action-fantasy story. This story introduces the important concept of "mud-bloods" (wizards with one or more non-wizard parent) and the theme of prejudice and bigotry shown by "pure-blood" wizards towards them.
Other than that there's not that much to talk about. There's more Quiddich, more mystery and intrigue. This story has quite a few more horrific elements than the first, ranging from giant spiders to a spell that makes Ron vomit slugs. Hermione (Emma Watson) disappears for much of the film's running time under an evil spell, requiring Ron and Harry to think for themselves for once. The ending feels like a generic action scene in any Hollywood film, failing to capture the magic that the book did. Of course some of this is just the fault of actually being too close to the book. Dumbledore's phoenix clawing out the basilisk's eyes is an exciting concept but as a CGI on screen (particularly since they chose to make the phoenix awfully small) it just looks silly.
One last word on the Gambon vs. Harris as Dumbledore controversy. Honestly as much as I respect Harris I just think he looked tired in this film and failed to capture the kind of energy that Dumbledore needs to have. Harris probably would have been an excellent Dumbledore if he had been healthy he's got all the screen presence that you need but none of the humor at this point in his career. I saw the first 4 movies before reading the books, and at first I felt Gambon was getting too goofy, losing the gravitas of the character. But after reading through the books I see that Gambon's performance is actually closer to what Rowling wrote. Harris' wizard is a bit more of a generic wise authority figure, where Gambon catches more of the particular side of Dumbledore that is sometimes wreckless and can be disarmingly whimsical  traits that make him seem less "authoritative" but certainly more human, and are of increasing importance in the 6th and 7th books.
All in all, I would argue that this film (like most of the others in the series) functions very well as a companion to the book but not so well as a stand-alone film for those who haven't read the series. Speaking as one who has seen the film both before and after reading the books I guess I should know. It's not a bad film, especially for those familiar with the details of the story that are left out which add depth (but which are not contradicted by the film for the most part), but it was a wise choice of the producers to hire a new director for the 3rd (and IMHO best so far).