20 Feet from Stardom 2013 ★★★
Ho hum.
It was fine. Not spectacular. Not particularly deep. Certainly not the best documentary of the year, especially when it comes to music.
That would be Muscle Shoals which has been listed as one of the 10 biggest Oscar snubs of 2014. I concur.
Although it was from the year before, another good choice would be Searching for Sugar Man.
Either choice digs deeper, presents a focused story, and does more than skim over the surface of people's lives.
You won't be wasting your time, exactly, in watching 20 Feet From Stardom. It is just that there are so many better documentaries to watch instead.