Travis McClain’s review published on Letterboxd:
Audio commentary with Academy Award-nominated director David Fincher
David Fincher's commentary track is one of the better ones I've heard, particularly for one guy to speak by himself throughout a film this long. He sings the praises of his cast and crew, but not in the stream-of-consciousness "She was so good this/He did such great work" manner that permeates most commentaries.
I was amused, for instance, by learning that Mahershalalhashbaz Ali was cast because Fincher had seen a commercial for a TV show he was on at the time (almost certainly The 4400, which enjoyed). Note that it wasn't even the show itself, but rather a commercial for the show that brought Ali to Fincher's attention.
Given that I'm going to write a comprehensive blog piece about the film for Flickchart, I don't want to redundantly write here what I'll wind up writing there, but I will share a gem from the commentary track that will almost certainly not make its way into that forthcoming piece:
"I don't really understand the logic behind it - it's a production management/VGA thing - whenever you're gonna use children, like infants, they always say, 'Get twins'...which is insane, because there's always a good twin, and a bad twin." - 2:17:35