Book vs. the movie

Just finished reading Raymond Chandler's "The Long Goodbye" for the first time, after having seen the Altman/Leigh Brackett adaptation numerous times. The book is a wonderful, albeit slightly long-winded at times, piece of detective fiction, raised a notch or two by Chandler's nearly-unparalleled use of the English language.

However, the screenplay by Leigh Brackett is nearly an original, as opposed to an adaptation. Very little of the book remains in the film, save for a few of the main characters and a couple main plot points. I always knew Brackett was one of her generation's best writers, but to take some as specific as a Raymond Chandler novel and basically rearrange its pieces into something wholly original is quite an achievement.

The film of THE LONG GOODBYE is, like the novel, very much of its time: the book being very late '40s/early '50s and the film practically a time capsule of early '70s LA and all its quirky danger. Both works are exceptional, but could almost be viewed as completely separate from one another, as opposed to an original and an adaptation.

Thoughts?