I'm pretty sure you can't read a Didion book and not recognize the power of her writing style. Unfortunately, I feel like I need to be an anthropologist, or perhaps a psychotherapist, to parse and value what she's saying.
I liked a couple of these essays a great deal, i.e., "On Keeping a Notebook" and "John Wayne: A Love Song", because they were simple but resonated with what I know or have experienced in life. Most of the rest were banal, such as "Slouching Towards Bethlehem" or "Goodbye to All That", which I chalk up to it being 50 years after the fact and everything about these places/venues/people has been done or said before. Or the essays were impenetrable, such as "Notes from a Native Daughter" or "On Morality", which just made me feel utterly dumb. Or they were of the - well, I have to write something or they won't pay me - ilk, such as "Where the Kissing Never Stops" or "Rock of Ages".
I'm not interested in needing a masters degree in literature (or anthropology or psychotherapy) to get something out of an essay. But I still think her writing has a depth and strength to it that makes me want to read something more penetrable by her. Perhaps her post-1960s work is more accessible?