It's taken us quite a while to get round to seeing this film. Perhaps I had been unnecessarily concerned that V wouldn't engage with its darkness, but in the end she really loved it...though the end itself was perhaps the one thing that disappointed her.
Critics have referred to the film's "daring originality". I suspect that many have become unused to movie narratives where character rather than plot is in the driving seat. The structure is certainly highly unusual; "a labyrinth," V suggested, unconsciously matching Mark Kermode's observation that you never really know what to expect next or where the story is heading overall. The film itself seems to seethe with the menacingly unpredictable quality of its central character.
She also described the experience of watching the first hour or so as a "tension tease", an effect that the score accentuates by insisting when it appears not to need to, and then dissipating during moments of dramatic crux.
Comparisons with Citizen Cane are perhaps deserved as much for the variety of little cinematic tricks deployed as for the subject matter itself. Given that the two mismatched antagonists at the heart of the film are unhinged representatives of capitalism and religion, one might care to look beneath the character study for themes of contemporary relevance, but other than the notion that these two callings have a benevolent self-identification tending towards malevolence, I suspect that Paul Thomas Anderson intended no schematic interpretation beyond our engagement with the phenomenon that is Daniel Plainview.