I was particularly fond of Doyle's use of natural light, the flickering techniques he used to let more/less light hit the film, and the subtle changes in depth of field. It was a joy to watch as I believe the last Doyle film I watched was Last Life in the Universe.
I've always been irritated with film trying to capture what it means to be a teenager, but this seems to get it right in so many ways. The feeling of disconnect, wanting sex but not really knowing why, the awkward conversations mimicking adults, the impressionability, and on and on. Like others have said, Elephant looks like an exercise into the angst and depression of youth compared to this.
As one who particularly enjoys the Portland area (I spent my honeymoon nearby), I enjoyed how Van Sant continues his visual and aural poetry of Portland. It seems to be as much a part of the picture as skateboarding.
I can't say enough great things about this one. I am eager to catch it again.
What other films does everything enjoy that captures the feeling of youth such as this? Amarcord comes to mind, but that's just me being lazy from the musical reference in Paranoid Park.