If you don't have plans to see this movie, you can check the spoilers here and then come back.
Near as I can tell, documentary maker Lauren Greenfield set out a few years ago to do a film about billionaires David and Jackie Siegel's attempt to build the largest house in America, but once the economic collapse hit, instead got the opportunity to tell a more complex and interesting story about the rich attempting to adjust and survive trying circumstances. If indeed this was not the movie Greenfield originally intended to make--and unless she's a financial wizard above and beyond anybody were on Wall Street in 2008 I don't see how it could have been--she did an incredible job course correcting, as this is a compelling, smoothly moving and well done documentary I don't think I could find much fault with if I tried (which I am doing). David and Jackie are fascinating subjects; initially you're tempted to roll your eyes at their excesses and revel a bit in their misfortune, and that seems to be the direction the piece is headed in, but as Greenfield introduces them through revealing and humanizing interviews, you find that they're actually pretty decent people and feel for their predicament. Yes, Jackie spends a ludicrous amount of money on seemingly trivial things, but it's wealth earned, both through David's hard work and her own determination (she's an engineer-turned-beauty queen who escaped an abusive first marriage). David comes off pompous and grumpy on one hand, but on the other genuinely seems to genuinely for the people he employs to the point where he becomes obsessive about saving his company even at the cost of his marriage. While the main narrative has enough twists to hold your attention, Greenfield effectively sets it against a wider backdrop by profiling tangential but important figures like David's son from a previous marriage who runs his company, the Greenfield nanny who is supporting grown children she hasn't seen in over two decades and more (at first I wasn't interested in Jackie returning to visit her old neighborhood in New York, but it has a payoff). Greenfield takes full advantage of the story dropped in her lap, capturing a microcosm of a much bigger American story and making a near flawless documentary in the process.