I read recently that this is the author's favorite of her works and, having read several of her novels, I can see why. It's not that the others are bad, it's just that this one is so good. I've heard it called a "family epic," but that doesn't do it justice. It has too much to do with people as individuals outside of their families to have the first word apply and "epic" makes you think of those novels that cover generations of a family, which this does but only technically.
I read it thirty years ago but remember it vividly.