I wouldn't call it his "best" -- but Sahara was definitely Tyner's breakout album. In that regard, Sahara is arguably his most important. It's a sort of watershed point in his discography.
Sahara also demonstrated that Tyner's "all-acoustic" group could compete with electric bands -- both jazz and rock -- in terms of sheer MAGNITUDE and FORCE. So there's some muscle-flexing involved that (to my ears) diminished as the 1970s progressed. This is a generality, of course; all of the albums weren't cranked to "11" -- but many were. (I think this is what @JSngry was talking about when he mentioned critics who described Tyner as a "pentatonic Oscar Peterson.")
OTOH, I should note that this type of thinking is heresy to many McCoy fans, particularly those who heard this music in the early-70s as it was initially released. "Full blast" albums Sahara and Enlightenment are the PINNACLE for many people.
However, I'm not old enough to have heard them in real-time as they were released. I've only heard the music retrospectively and out-of-sequence. And I've discovered that I prefer the stuff that has a bit more air in it, that breathes a little. For the most part*, the early stuff ain't that.
* An exception that proves the rule: I think Sama Layuca (1974) is one of McCoy's best -- because it ebbs and flows. Bobby Hutcherson's soulful presence dials things back (a little); his voice adds some chill to the proceedings. Unlike Sahara (and other albums like Enlightenment or Atlantis), Sama Layuca strikes me as being musically balanced. It's not triple-fortissimo all the time.