First, the caveat: I go through exactly the same process with every Gus Van Sant film I've ever seen. Immediately after it's over, there's a state of bliss brought on by the director's exceptionally idiosyncratic style. After a few hours, that fades into a serious appreciation of what he achieves with his technique, coupled with the suspicion that it's a little bit too heady, more of a math problem than a movie. After about a week, like a switch being flipped, I suddenly can't figure out what I liked about the film at all, and that is where I remain for the rest of time.

I waited as long as I felt right, but it hasn't been a week since I saw Paranoid Park, the director's Cannes entry from 2007 finally making its US tour. So right now, I pretty much admire it, and I'm going to talk about it from that perspective. Ask me in a few days if I'm not totally horrified by everything that follows.

A film without a plot - though it surely does pretend to have one - Paranoid Park is an observational study of the skater culture in Portland, Oregon, although that phrasing implies that it's something like a documentary. This could not possibly be less true. It is a lyrical, impressionistic work, its finest moments decontextualising the content it shows nearly to the point of abstraction, overlaying an entirely unexpected soundtrack of Ludwig van Beethoven and avant-garde electronic instrumentals atop footage of skateboarding teenagers.

The film begins and ends with extended wordless sequences of these skaters performing simple tricks in lengthy shots, filmed by commercial and music video DP Rain Kathy Li on Super 8 film; similar sequences recur throughout. When even the cheapest of independent movies can manage to afford fairly sharp HD video, the effect of seeing something so archaic and low-resolution as 8mm film on the big screen is revelatory: grains the size of your thumb, colors that look like a 40-year-old photo album that's been stored in a damp basement, and the most fluid and balletic camera movement I've seen in a theater in 2008. Add the already hypnotic and repetitive music that Van Sant uses to score the skating scenes, and you've got something that doesn't feel like a movie at all, but more like the dreams of a restless subculture. For these sequences alone, I would call Paranoid Park a masterpiece & the most exceptional work of Van Sant's career.

Those scenes are, however, absolutely the best part of the film, and much of what remains is fairly reminiscent of the director's sometime-maligned work in Elephant; basically, those who have been entranced by the director's recent "experimental" phase will be entranced by Paranoid Park, while those who find those films chilly and pretentious will doubtlessly have a hard time with the new one. Those who take a week to make up their mind will just have to wait a bit for my opinion.

After his loosely-connected "Death Trilogy," Paranoid Park feels like the first step back towards a more conventional form of representation for the director: it is a bit more script-reliant than Gerry or Elephant (I haven't seen Last Days), though that's a very relative way of putting it. It follows a period in time in the life of Alex (Gabe Nevins), during which the stress of his parents' divorce and his girlfriend's relentless sexual badgering drive him to spend more and more time at Paranoid Park, a real-life underground skating park in Portland. There he is involved in a terrible accident that results in a man's death; this also adds to his stress.

It's a sign of Van Sant's priorities that Alex's reticence about sleeping with his virginal girlfriend is a much more significant part of the film than the extraordinarily gruesome death he witnesses. This isn't about what happens, or even how Alex responds to it; it is about how he experiences life at a stressful time, and how his pinched-off existence starts to fall apart without providing any valid replacement. The main bulk of the film has been shot by Christopher Doyle in what I strongly believe to be his best work for any director other than Wong Kar-Wai; everything, even the sunny outdoor days, feel washed out and grey, and there are virtually no sharp shadows - no clear divisions between light and dark - only smooth flatness.

Unfortunately, it's difficult to fully appreciate Doyle's work in the film in its current release. Paranoid Park was composed to be screened at an aspect ratio of 1.37:1, but as far as I have been able to learn, it's not being projected that way anywhere in the country - I've found a few sources claiming it's being shown at 1.85:1, although where I saw it, I'd have guessed 1.66:1. Either way, it leaves the film feeling inordinately cramped; not claustrophobic in a way that might have been appropriate, but rather full of awkward head space that looks simply appalling, and completely ruins at least a few theoretically brilliant shots (a close-up silhouette of Alex's head in the shower, water running from his hair in streaks, is the most tragic victim of this problem).

If for no other reason than the contrast between the Super 8 and 35mm, I'd be comfortable calling the movie a formal masterpiece and Van Sant's best film. And make no mistake, on formal terms it's absolutely worth seeing. Sadly, the art of cinema isn't just about formal elements. For one thing, it's about actors, too. Actors, in this case, that Van Sant cast off of MySpace; actors who were almost all non-professionals. It's not the first time the director has played that card; Elephant was the same, without the internet gloss.

The assumption that casting "real" people means that the characters will seem rawer and more realistic has existed at least since the 1940s, and it's been a terribly misguided assumption for just as long (I get to say this, because casting non-actors ruined the only film I have ever directed - ruined it but good). Sure enough, Paranoid Park starts to fall apart on the performances, which have many defenders, and I'm happy to live in a world where people like watching movies with this kind of style of acting. Me, I couldn't fucking stand Gabe Nevins; as long as he kept his mouth shut and looked pretty with his thousand-yard stares, I was fine, but whenever he tried to deliver a line of dialogue, I could feel my ears crying. He was not, by a long shot, the worst performer in the film; I'd not like to name names. I don't blame him. I don't blame his colleagues. I blame the hell out of the director, who has confused clumsiness with a lack of affectation, and poor line readings with teenage awkwardness. It's painful to watch, and I don't give a damn what effect it was supposed to have, the only effect I noticed was my own acute embarrassment for everyone involved.

This is not, perhaps, the stuff that good character studies are made of. Once again, ask me what I think this time next week.