I love Sparks and thought the documentary was fantastic. I first heard of Sparks in the 80s but only because two artists I loved covered their songs -- "This Town Ain't Big Enough for the Both of Us" by Siouxsie & the Banshees and "Never Turn Your Back on Mother Earth" by Martin Gore.
I didn't really get into Sparks own discography until 10 years ago or so and was flabbergasted by the depth of their catalog and how ahead of their time they were. Somehow I always knew they were from L.A., but for a long time I thought they had a female singer! Russell Mael still sounds great.