Less charitable viewers are saying that he seems restrained and apologizes for saving his voice, because the person we see isn't Jackson at all, but a stand-in. I doubt this is true, but the Jackson characteristics I know are the obvious things a stand-in would be able to duplicate: the whispery way of speaking, the constant sunglasses, the smile that appears tentative until those around him smile or laugh first.
The documentary itself is as odd critter. It does contain actual film footage that was going to be used in the show. There are forest scenes and a pair of special-effects extravaganzas, one to accompany the song "They Don't Care About Us," and one to update "Thriller." The rest of the picture is essentially Jackson performing with varying degrees of conviction, and singers, dancers, musicians and tech folks genuflecting whenever they make eye contact with Him. It's not much of a movie, but it's one hell of a worship service.
I felt uncomfortable with Jackson on-screen when he wasn't performing. His pickiness over every detail has been described as some kind of genius, but it comes across to a viewer not in the man's thrall as micromanagement of the most annoying sort.
At one point. he tells guitarist Orianthi Panagaris to take center stage. "This is your time to shine," he whispers. Fine, except then he adds, "We'll be right here with you," and he tells her what to play for her solo and how to play it. There's a word for that, and it ain't "genius."
So here's the bottom line: Die-hard idolaters will love this movie; those who like Jackson's music but don't laud the man may be disappointed with his performances; those who don't care will continue not caring.
As for those who think of Jackson as a faded memory from the early '80s, well, when the vamp for "Beat It" began booming out, I thought of "Weird Al" Yankovic and smiled.