This is a very interesting tune, partially because it only has 10 chords. Instead of feeling like a piece, with sections, it sounds more like a circle that the combo just follows around and around until they feel like ending things.
The melody, when Davis does play it, is incredibly rubato (which isn't anything new or surprising), and the musicians use very extended harmony, which is also typical of this combo. I mention these things however, because the combination of those factors made it almost impossible to follow along with the combo through the changes.
I'm also amazed at how much the chords seem to make sense when I hear them played by this group - I've been struggling to make them sound like any kind of coherent progression in my jazz piano lessons.
There is no clear tonal center - the only major chord in the piece is a Bbmaj7#11 which occurs only twice, and isn't the last chord. There are four ii-V progressions, three of which are A-D and don't resolve to G, which the listener expects. The fourth ii-V does resolve to Bb, giving the piece some sense of a tonal center and at least one cadence.
This piece made me feel relaxed, like most of Miles' music. If I hadn't had the chord progression in front of me, and wasn't trying to decipher it, I probably would've enjoyed it more for the sound that makes Miles great - cool. However, looking at this piece from an intellectual standpoint makes it a bit of a headache.