The Mick Taylor Years, sadly enough, began with the departure of Brian Wilson from the band, followed quickly by Wilson's death. The first live performance Taylor had with The Stones was a memorial concert for Wilson, a fairly grim beginning to his stay with the band. The next five years saw The Rolling Stones release classic albums like Sticky Fingers in '71, Exile on Main Street in '72, and It's Only Rock 'n Roll in '74, which would be Taylor's last full album with the band. Prior to joining The Stones, Taylor cut his teeth with John Mayall's Bluesbreakers, filling a pair of rather large shoes left when Eric Clapton departed the Bluesbreakers. Other than some notable performances, Taylor's career after The Stones was unexceptional, but The Rolling Stones 1969 - 1974 does a nice job illustrating what he did as a Stone that made him such a standout.
There's some speculation about the bad stuff, but a consensus opinion on The Mick Taylor Years is that Jagger's and Richard's resistance to sharing song-writing credits led to a rift. In his five years with the band, Taylor was only credited as a writer on one song, and residuals on writing credits are where the real money comes from in this business. How much writing Taylor did is up for debate, but no one denies that he brought something to the band that really came to define the sound of The Rolling Stones. Traditional rock guitar, country strings, raw funk sound, and lyrical solo lines flowed out of Taylor's guitar, complementing the more raw musicianship brought by the likes of Keith Richards. At one point in this film, the comment is made that while his successor Ronnie Wood was likely a better team fit for the Stones, Taylor was a superior musical complement, especially as a foil for Jagger.
Regardless of how strongly you feel about Taylor, The Rolling Stones 1969 - 1974 - The Mick Taylor Years does a nice job of walking through each pivotal record in this period, and covers in-depth the recording sessions, band relationships, and key cultural changes happening during this period. It's required viewing for any core Stones' fan, and it will even give casual fans a new appreciation for the history behind tracks that have worked their way into popular culture.