OK, the scholarship is impeccable, but who is this for? If you don't know the music, the descriptions of the bands and the albums don't do much for you. On the other hand, if you're such a Miles fan that you have all this stuff, why do you need Richard Cook telling you what you're hearing? You've probably read the liner notes to the CD's or boxes, and it doesn't seem to me that there is much that he adds. This seems to be mostly an expansion on Cook's writing on Miles's music in the Penguin Guide, and if you want to know his opinion as to which CD's to buy, I'd take a look at that instead. As good as this is, I'm not sure why you'd buy it.