Good stuff. More to say about this but two prelminary thoughts:

1. Matt Zoller Seitz is always worth reading, but the best thing he's done are these video essays that pretty much obviate dvd commentary tracks. Here's one about Wes Anderson: http://bit.ly/kNFzB (to get the video to play, click the link below the picture on the right). Apparently, Criterion is going to include one of his video essays on their DVD of the Darjeeling Limited.

2. The Chinatown-as-best-screenplay-ever thing is one of those statements that somehow became conventional wisdom without anyone ever defending it, but here's a defense: http://nyti.ms/bCI1GS

Basically, I think you're underestimating how much the protagonists in noir films typically accomplish. (And even in a "good intenton" movie like The Third Man, Harry Lime dies. In the Polanski/Towne version, Harry would shoot Anna in the stomach and the doctors would give her Harry's penicillin). Also -- the visual puns on Evelyn's eye are all in the screenplay, down to which tailight gets smashed. There aren't many screenwriters who poke their head into the narrative like that (the model would be Nabokov's "travesties of familial feeling" in Lolita), and I can't think of anyone who did it that gracefully (and for such a sick joke). Hope that makes sense; Chinatown isn't my favorite film, or even my favorite Polanski film, but I see what people see in it.

The screenplay itself is here as a PDF: http://bit.ly/9JdxQh