When focusing on a documentary subject like Muhammad Ali, who has been picked apart by storytellers and journalists almost ad nauseam and will continue to be until the end of time, it is easy to fall into the trap of re-hashing all the classic stories and losing focus on the uniqueness of the concept that may have prompted the new doc on him. While "Ali & Cavett" isn't bad by any means, it does spring that trap far too much to be considered "great".
Ostensibly, the angle on Ali that this documentary takes is examining The Greatest via his appearances on the popular 1970s TV talk show hosted by Dick Cavett, who was able to get some candid and genuine moments from the gregarious Ali when others failed at the task.
Those interview clips are indeed fascinating, and in terms of the info this doc presents on Ali's involvement within the Nation of Islam (and how he was very likely used as their puppet/mouthpiece), it did provide me with some interesting information to chew on. To be honest, I wish the entire runtime would have simply focused on those two concepts (Cavett & Ali's religion/politics). Had that happened, this probably would have received a higher star ranking from me.
As I said in the opening, though, "Ali & Cavett" spends too much time re-hashing Ali's boxing exploits and showing the same clips or sound bytes we've seen over and over already. Ali's larger-than-life status likely renders this too irresistible for the film makers to avoid, especially if roping in casual viewers is important (and it always is). For someone like myself who has "seen them all" when it comes to Ali docs, though, a solid 70% of this one is "old news".
So, while I can't say this is a bad documentary by any stretch of the imagination, the amount of fresh, new material is relatively small within in. As such, your enjoyment of it overall may be determined by your previous Ali knowledge level.