I finally marathoned this whole thing.
For the bulk of its extensive running time, it's an absolutely fantastic look at the design and execution of the most storied theme parks and attractions on the planet, presented in a glossy -- but relatively frank and honest -- way. The amount of archival footage here is nothing less than a goldmine for fans, and the way it highlights the numerous personalities who had their hands in the creation of Disney’s themed entertainment is very important for posterity. The evident passion and emotion on display from these folks is quite heartwarming to see.
Things do sputter out in the last two episodes, however, where it becomes clear that making Bob Iger’s decisions look as good as possible was a major goal, to the detriment of the overall package; Iger’s legacy with the theme park side of Disney’s business will (in time, I believe) be viewed as incredibly mixed, not the resounding triumph of wisdom and good taste which it is depicted as here. The fluffery starts to come out in full force, and any discussion of internal conflicts is buried. Obviously, nobody should have been expecting this to slam the regime that greenlit this project, but a bit more objectivity -- and fewer pulled punches -- would have been greatly appreciated. The multi-billion dollar boondoggle of “Next Gen”/"My Magic+” and the stagnation of the Florida parks from 2009 to 2017 should carry at least as much weight as the discussions of the creative and/or financial underperformance of the two Paris parks and California Adventure, but since the latter can be pinned on Michael Eisner and not Bob Iger, the former are ignored.
So that closes things out on a more sour note, but everything leading up to the mid-2000s through 2010s section of this massive documentary highlights the superb fusion of creativity and practical application that has defined the very best work of the Imagineers since the 1950s.
Overall, essential viewing.