New York's skyscrapers, and unconventional sources

For my other course, we had to read this piece about the "skyscraper boom" in New York City, and discussed the sources a bit in class--a discussion I thought might be of interest here. Besides being gorgeously written, the article uses a variety of sources that might not fly in "hard journalism"--poetry, an (unscientific but interesting) study of skyscrapers the author photographed, and a blog. All this is admissible here because the piece toes the line between feature, personal essay, and criticism. Our teacher also pointed out that many other news stories about skyscrapers had run by the time this piece came out, so Davidson's more thoughtful approach was necessary to make the piece more appealing. I'd love to hear your thoughts on how Davidson would have had to change this if it were a news piece, and also how his techniques might be integrated into our own writing.