Saw this last night and was blown away by it. For me it played as an intense psychological study of infidelity and addiction. The performances are taught and understated, as is the direction, with attention often focused on minute details.
I've seen negative reviews of this film from two different perspectives. One is the art-house maven who feels the scenes of sexual violence are gratuitous and in poor taste; Kevin Maher's comments in the Guardian are an example. Once these reviews have had an airing they tend to attract gorehounds, some of whom (going by online reviews) had been led to expect a genre movie and were disappointed. Hence you get a lot of complaints about slow pace, unresolved endings, lack of gore etc etc.
The movie does contain some quite disturbing scenes, but they serve to heighten the emotional drama that the film's really about rather than being an end in themselves. You've probably seen plenty of things more graphic than this without straying into the outer reaches of the horror genre. The sexualisation of the violence does make it more potentially upsetting, as does the psychological context Denis so delicately builds up.
As other reviewers have said, this isn't supposed to be a plot-driven action movie, but the storytelling is impeccable. The ambiguous ending is absolutely logical, and people who say it "doesn't end properly" astonish me. The ending makes perfect sense in light of everything that's gone before.
The back-story about the pharmaceutical company etc is pretty cheesy, but it helps to have some kind of nod towards an explanation for what's happened to the lead characters, and that's really all it is.
I think this one is going to stay with me a long time and I'd definitely re-watch it.
