I think the key to understanding Miles is found in a basic premise; a premise that is controversial for many listeners and which is at the heart of a lot of the "bruha" (to quote O-10) on this thread. This basic premise says that the artistic success of any music is determined by how well it expresses or represents the time of its creation; not as compared to an aesthetic or strict standard of excellence from the past. Moreover, whether we like what any music is saying about the time of its creation or not is besides the point. Personally, I am of two minds about the validity of this premise since certain standards are timeless; but, I have to acknowledge the "purity" of this premise and I see a basic and pointless conflict in always applying standards that only go back in time. Time moves forward; whether we like it or not.
Miles was the quintessential example of this premise and, by that standard, the album "Tutu" is a success. Considered by some his last great record it is a great example of much of what was going on at the time with the use of electronics and atmospheric textures. His trumpet playing is in really good form (timeless standard) whether we like what he is playing or not. Whether the music is "jazz" or not is also besides the point. I personally don't think it is and the fact that Miles used to play jazz as most of us know it means absolutely nothing in this context and shouldn't influence how we judge this music, imo. He was never a slave to the past and always felt his mission was to represent the present and, if anything, nudge it forward not backwards. Still, and accuse me of looking backwards, but, for me, 60's Miles is still the pinnacle of his career and represents the best balance between the timeless standards and the new.
Ghosthouse, your comments about the economy in Miles' playing is spot on.
"Its not the notes you play, but the notes you don't play" - Miles Davis
"You have to know 400 notes that you can play, then pick the right four." - Miles Davis