This is very much after-the-fact, but the lateness of this review reflects that I simply had no desire to see this movie and only did so because I could as part of, shall we say, a 2-for-1 situation (a review of Southland Tales will be up soon). Nonetheless, I saw this out of a sense of duty to have an informed opinion about the most lucrative horror franchise right now, and also to have an excuse to rant about how much I hate these movies.
The original Saw was okay, a decent locked-room dramatic situation for the most part. It was mildly enjoyable except for some obnoxiously trendy music video-style editing and Cary Elwes' terrible performance. But when the baton was passed to first-time director Darren Bousman with Saw II, everything went downhill fast. The first movie had established the character of Jigsaw (Tobin Bell), an engineering genius and victim of terminal cancer on a mission to teach the world something about the value of life. Fine and good as a gimmick in the first movie, but Bousman's direction was to foreground Jigsaw and make him the center of his movies as a sort of world-weary antihero. Interesting concept, but Bousman lacked the imagination, moral compass, and directorial chops to pull it off.
Jigsaw is obviously an extension of both Hannibal Lecter from Silence of the Lambs (the serial killer-as-guru, smarter than everyone else and with no qualms about playing by his own rules) and John Smith in Seven (on a mission to punish those he deems in need of moral rectitude via gruesome torture). Jonathan Rosenbaum has written about how much he hates the serial-killer-as-moral-authority trend specifically as it appears in both Silence of the Lambs and No Country for Old Men; I don't think he's right about either of those movies but I think his argument applies well to Bousman's Jigsaw. The point of Seven was to watch how Brad Pitt and Morgan Freeman are changed via their confrontation with a sociopath; it's a film about characters under stress with the 'seven deadly sins' gimmick merely the macguffin for the rest of the plot. The point of Saw II-IV, on the other hand, is to watch characters jump through Jigsaw's hoops, only to discover at the end that nobody is capable of living up to his 'moral standards'. Where Fincher and the Coens are interesting in asking questions about morality and our place in the world, Bousman has the balls to speak, via Jigsaw, as a patronizing and childish moral authority. The characters and their moral issues have become the macguffins, and the sullen, insistent gore has become the point.
Now, gore for gore's sake isn't necessarily a deal-breaker as far as I'm concerned - it's one of the primary reasons to watch a movie like Dead Alive or Dawn of the Dead. The problem with Bousman's filmmaking is twofold: his insistence on making his movies so humorless, so utterly intent on 'scaring' his audience in a drab, grim manner that I can only call pretentious and hollow; and his utter incompetence at filmmaking. All three of his Saw movies feature terrible acting and annoying cinematography and editing. Craft matters, and it's bizarre that Bousman apparently considers himself to be a horror movie fan, because you wouldn't know it from looking at his work - his movies appear to be made by an aging hack intent on trying to appeal to a youth audience through camera and editing gimmicks.
So that's the deal with the franchise in general; Saw IV in particular stands as the worst of the series so far, thanks to a bizarre insistence on trying to cram in plotlines and characters from all four movies and a bewildering narrative that I couldn't make heads or tails of by the end - I suppose patient attention and multiple viewings of the previous movies would clear some of this up, but I just didn't care why Angus Macfadyen from Saw III was suddenly reappearing or how the multiple flashbacks pieced together.
So what makes the difference between Bousman's movies and Eli Roth's movies, which I'm a fan of? The basic answer would have to be mastery of tone and, believe it or not, restraint. Bousman's movies are thudding, obvious, and deadly serious, while Roth knows how to shoft moods from terror to comedy to absurdity. The most chilling moment in Hostel Part II is a scene involving the kids in the woods and how they turn on each other ; it's simple, quiet, Hitchcockian, and has no counterpart in the Saw sequels. You can tell just by watching Bousman's movies that he doesn't know what he's doing, and more importantly, he doesn't really care.