Without wanting to repeat what so many have said, I just want to quickly add to the other reviews that the packaging for this item is terrible. Very tasteful, very solid on the outside, but the disc trays are shocking. Many people familiar with DVD box sets will have seen great systems in use to overlap discs or otherwise make use of little space. This is NOT like any of them. Difficult to get discs in and out, potentially leading to scratches, bending of discs or even breaking discs if you're not the patient, careful type.
The music is amazing (I have 90% of it elsewhere, and the sound quality of this is just as good as single discs). The book is pretty good, obviously don't expect anything too detailed.
In short - Great value for money, ideal starting point for a newcomer to Miles (or a collector looking to get all the last bits and pieces), awful packaging.