Saw Kill Bill last night with SL and J (coincidentally, it looks like MS did too). The advance buzz has mostly been about the excessively gory, relentless, and conscience-free violence, which I did find annoying and cheap --- in a culture where a murderous robot can be elected governor, it doesn't take much imagination or courage to make a movie that merely depicts even more trivialized violence --- but I thought the real failure was that the action simply wasn't shot that well. Yes, I know this seems like a ridiculous assertion, given Tarantino's obvious visual fluency in general, but bear with me.
Tarantino shares the misapprehension, disappointingly common among American blockbuster directors, that the point of cinematic action is its result: he's quite careful to convey that the table gets knocked over and smashed up, or that so-and-so's body part gets hacked off, or that the blood gets splattered against the walls. But he fails to portray effectively the motion of the human body, which, for me, is what it's all about. Action is a form of dance. Well-executed action has a certain rude grace, and for me it's only satisfying when the film captures that grace visually.
It's instructive to compare the fight scenes in Tarantino's film with those in The Matrix or Crouching Tiger, Hidden Dragon. Of course, those other movies had quite different aesthetic aims, but all three share the same choreographer; and the Wachowski brothers and Ang Lee were both, in their own ways, vastly better at showing you the action than Tarantino. When Morpheus and the Agent are fighting on top of the 18-wheeler, you never doubt for a moment exactly how the Agent knocks Morpheus over the side. You grasp every instant, every block and punch and reversal, and you can appreciate the impact of each individual motion. Likewise with Jen Wu and Shu Lien's first fight, following the rooftop chase sequence; this fight was additionally masterful because the specific motions of the fight/dance were actually an embodiment of the differences between their characters. Swashbuckling, romantic rebel Jen Wu repeatedly tries to take flight, and is pulled back to earth by Shu Lien, whose misguided attachment to tradition later dooms her own love. Compare these to Kill Bill's climactic showdown between O-Ren Ishii and Black Mamba: the swords clash (you can't tell how they clash; you see steel flashing and you hear the clang, but you don't know what's really going on); Uma Thurman falls; Uma gets up; the swords clash again; Lucy Liu gets scalped; game over. The difference between Ang Lee and Tarantino is like the difference between a comedy with genuinely funny, sharply-written dialogue, and one where the dialogue makes no sense but you know it's supposed to be funny because of the laugh track.
In short, Tarantino's movie depicts not so much action itself as the idea of action. Tarantino makes all the right manneristic cinematic gestures associated with action, and he positively relishes the gory result of action, but ironically he doesn't have much sensibility for the action itself. He's better at showing gushing blood than bodies in motion.
Now, all that said, Kill Bill wasn't exactly a bad movie. The music was great, and the film's packed with visual style. There's a cool anime sequence, in which the action's actually quite effectively conveyed (which is ironic, since there's much less motion in this sequence than in, say, the big swordfight in the club). But in a movie with so little of dialogue or character, the action's all there is; and if that's not spectacular, then the movie can't really be entirely satisfying.