I watched it, start to finish. I liked some parts. Overall, I'd say meh, mostly because of the way it was made.
*SPOILER ALERT*
They interviewed as many drummers as they could find (or afford) within their time constraints. They then grouped clips into half-a-dozen or so categories, based on the commonalities of what was said in the interviews. To give it a little bit of a narrative structure, and to keep viewers hanging on for a promised surprise at the end, they periodically interspersed segments of a drummer putting together a perfect kit (perfect for that upcoming performance, at least).
Given that the filmmakers were at the mercy of what people said, I think they did okay. It's just not my favorite style of telling a story.
My wife watched it, too, and gave the producers props for including more female drummers than usual. And given that she has been hearing about Neil Peart from her brothers pretty much nonstop for half a century, she didn't mind that omission.