There is but one thing more annoying than wanting very much to love a movie, only to find out that it kind of sucks: wanting very much to hate a movie, only to find out that it's pretty good. Other than its atrociously over-compensatory subtitle, Precious: Based on the Novel 'Push' by Sapphire is at all turns interesting at the very least, and often quite effective. It also comes absolutely nowhere close to justifying the torrent of hype that has preceded it in the 10 months since its Sundance debut, and its locked-in-stone Best Picture Oscar nomination serves in my case only to remind me that I am not the same kind of person that Oscar voters are. But even when director Lee Daniels overplays his hand the worst, the film is always wholly worthy of discussion.

If you have remained blissfully free of the impending tsunami lo these many weeks, Precious: Based on the Novel 'Push' by Sapphire* is the story of Claireece Precious Jones, whose life in 1987 Harlem is about as unfathomably terrible as you could possibly find: made pregnant by her father for the second time (and her first child has Down syndrome), living with a wretched viper of a mother ironically named Mary (Mo'Nique), illiterate, and treated with a callous lack of even the slightest affection by every person in her life, Precious is also afflicted with a body about as far from the American mass media's standard of beauty as can be designed: she's tremendously overweight, and she has black skin: not the mocha-colored skin of most mainstream-successful African-American actors and musicians, but a deep, dark brown. Filled with constant reinforcements that she is totally valueless, Precious frequently lapses into fantasies in which she is either the dancing star of a BET-style music video, or where she sees her reflection as a skinny white girl with luscious blond hair.

Hope comes in the form of an alternative school program called Each One Teach One, where she is introduced to the saintly remedial English teacher Blu Rain (Paula Patton), who forces her and a classroom full of other troubled urban teen girls to write anything that comes into their heads in a journal, a grossly hackneyed inspiring teacher movie cliché that somehow manages to work here because it's not actually the case that the mere act of writing saves - or even necessarily helps - the girls. As the movie goes along, things manage to actually get worse, as Precious's home life deteriorates past it already horrific level of depravity, and she learns slowly but surely that there really is some value to her life besides cooking dinner for the demon-mother lying at home, curled up in front of the television at all hours of the morning and night, rousing herself only to convince the social worker that she still deserves to receive welfare checks.

This could very easily descent into claustrophobic miserabilism at its worst, and in fact it does, sometimes. But Precious: Based on the Novel 'Push' by Sapphire never comes across quite as mawkishly manipulative as I feared. This is mostly because Precious herself never makes any demand on our sympathy, and for this we must credit Sidibe, chiefly; the first-time actress really is every bit as extraordinary as you've heard. Playing her character by turns first as stiff, dull-eyed and mumbling to the point we can barely hear her, then singing and dancing with joyful abandon in the fantasy scenes, and back to the real-life settings, in which she grows increasingly comfortably in her own skin, breaking sometimes into the shiest of smiles and speaking with less reluctance and more authority. At no point does she mug or act like a browbeaten puppy, begging for our affection. She plays Precious as a girl who literally does not comprehend that she is unhappy, because she has no concept of "happiness" to measure herself against, this effectively eliminates any temptation to milk the audience's sympathy. But just describing the arc of the performance does it a profound disservice: Sidibe inhabits all the various angles of Precious with a particularity that would do credit to an actress with decades more experience - it is among the finest acting debuts I can ever recall seeing in a theater.

The only person involved who really seems anxious to make sure that we Feel! and are Outraged by the Senseless Inhumanity Of It All, and are Enheartened by Precious's rising awareness of Her Own Value, is Lee Daniels, whose direction veers madly from the effective and well-considered to the batshit insane to the plain irritating. I am not all sure what I feel about the fantasy sequences presented in the movie: and more to the point, I am definitely unsure what Daniels and Geoffrey Fletcher (who adapted the screenplay from a novel by Sapphire) felt about those sequences. As indeed I am generally uncertain what to make of most of Daniels's little touches of representation; if a white person made Precious: Based on the Novel 'Push' by Sapphire, with its welfare queen villain and its general enthusiasm for exploiting the nastiest elements of poor African-American life, it would undoubtedly be seen, correctly, as racist. Except that a white person didn't make it; and that does actually make a difference. One that I am ultimately not qualified to judge, although it strikes me that Daniels doesn't even seem aware that somebody could actually be troubled by his film.

I have no problem criticising Daniels on other grounds, however, such as his baffling use of handheld camera and zooms to over-emphasise moments that don't seem to need it. As well as the fantasy sequences, which typically err on the side of garishness (the strange riff on De Sica's Two Women is an especially noteworthy example). It's almost tempting to say that the director doesn't trust his material, and feels the need to make sure we get it by constantly hitting us over the head, but that's not quite right. Rather, I'd say that he merely lacks the critical distance to realise that he's adding sledgehammer melodramatics a story that needs at all costs to avoid slipping into meldorama and thus into sheer audience-hating misery.

It's the cast that really saves the film from this fate. Paula Patton is nicely restrained as a standard-issue teacher with a heart of gold, reigning in the mustiness of that character type by anchoring her in small gestures and emotions; Mariah Carey is, amazingly not even a little bit horrible as a social worker, but rather disappears completely into the role, mixing horror with the bland understanding of a bureaucrat who's seen it all in a heady little performance that suggests that Mimi is chasing down entirely the wrong career.

But the standout, for good and ill, is Mo'Nique, who is absolutely transfixing as the acid-spewing Mary. The character on the page is nothing but one big Oscar clip moment after another (though Oscar clips usually lack so many examples of the word "motherfucking"); but Mo'Nique - who, let us not forget, is a comedian - embodies those hammy moments in a character too evil to be real, but who is so absolutely present that you can not for one second doubt that yes, she truly exists, right there in front of me. The filmmakers frankly don't know what to do with her, to treat her as a cartoon of depravity or an actual source of terror and danger; and the degree to which the character is already an insulting reduction of a real-world situation is something I dare not do more than speculate about. But it's not Mo'Nique's fault: she tears across the screen like a roaring hell-hound, all the way up to her deeply tearful, self-deluding, pitiful and wicked final monologue, and thus the film ends up boasting two of the most amazing performances of 2009, though they could not possibly be more different in style or effect.

I think, maybe, that these two actresses account for Precious: Based on the Novel 'Push' by Sapphire's rampant success: tastemakers like bravura acting. So do I, but it doesn't obscure the fact that there's just some really clumsy behind-the-camera work going on here: ill-chosen directing and some truly rough editing in spots (and yet in others, it could hardly be improved. Go figure) that keep the film grounded in formal stickiness, and a gruesomely depressing tone that is just a little bit too close to leering ghetto porn for me to be entirely comfortable with what I'm seeing.