I could never mark a CD down on packaging grounds personally, but may mention this in the review. I personally prefer the Impulse CD packaging to the oh so awkward jewel case.
Anyway this album is just superb - and shows off Gil Evans great skills as a consummate musician/arranger/conductor, and happily sits in my collection along with the 3 more widely known Miles Davis collaborations (Sketches of Spain/Miles Ahead/Porgy and Bess). From the opening piano on Nevada, with such a glorious intro, through a further 5 pieces covering a wide emotional and dynamic range, it allows a degree of introspection whilst providing novelty and stimulation in equal measure. I would not want to isolate any particular piece but celebrate the unity of the album, covering Gil's work in it's entirety.
So, a very high recommendation - representing jazz orchestra rather than big band as such, if such a difference can be made. Exceptional!