I'm a big fan of the original book by William Knoedelseder and this at best is a loose, and entirely fictional adaption. I love documentaries and perhaps a bit disappointed this wasn't.
At first I found the slower pace and dark themes somewhat offputing, but got drawn in after watching the first episode. The period costumes and facial hair were amusing and you find yourself rooting for the comics to get the Carson couch.
Perhaps the most engaging and addictive things about watching this film are the easter eggs of fact and the puzzle of what elements from the actual people are placed in the stories of the fictional characters. There are no one-to-one correlations; it's very much mix and match. Each character says and does myriad things plucked here and there from actual comedians documented in William Knoedelseder's book. For those that read the book or were fans of standup comedy of the time will have fun guessing which morsel of reality ends up in which character's story.
One big gotcha - the series is listed as the entire season but the discs of the multi-disc set are sent out individually and each counts a credit out of your subscription level, so be prepared to watch only 3 episodes at a time.