Still my subjective appreciation of the music.
Free jazz is the ultimate symbol of everything that is important in life : absolute freedom, openness of mind, listening to others, creativity, emotional wealth and intelligence (tough luck for those who're interested in money : it won't make you rich). No musical form is as open as free jazz : because of the lack of an imposed format, it is easy to incorporate other music. That was one of Don Cherry's great missions - to integrate the muscial wealth on earth into his own music.
Free jazz means going against patterns, leaving the beaten track, including your own. That is one of the reasons why free jazz is so difficult to play. Most musicians have automatisms and routines in their play, patterns in the fingers that take over spontaneously once they start improvising. The real improvisor has to let loose of these patterns. Not an easy task. On top you have to be able to listen closely to the other band members and take over tunes of changes you've never heard before, and do something creative with it.