Okay, right off the bat let's get this out of the way: Jane Smiley's A Thousand Acres is King Lear told from the perspective of Regan and Goneril (Rose and Ginny). That's fine, but I actually want to approach the book independent of the Lear connection.
The writing is pretty dang great, honestly. I was expecting the book to be dull and slow but I read the whole thing in a single sitting - it was really engaging and brilliantly paced; it also has this stellar midwestern gothic thing going, you know, swaying corn and abandoned charity shops and churches no one really wants to go to. The grimness and drudgery of farm work and the incomprehensible multi-generational dedication to it.
I kept feeling like the book was familiar and it wasn't the Lear thing, it was Stephen King's 1922 and Truman Capote's In Cold Blood. It turns out that "something evil is lurking in she barn" or "these fields have many secrets" is an aesthetic that I'm super into. Smiley does that aesthetic really well and the faded mysteries of the junk pile and shimmering heat of the fields are tangible and harsh, as is the driving wall of water from the unexpected storm and the cool earthen rot of a cellar unknowingly housing a poisoned pill.
There's an unsatisfying tension at the end of the novel and I think it's actually pretty brilliant. Things aren't neatly resolved, people aren't happy ever after. That kind of makes it stick. I finished this book about three weeks ago but it's been in my head enough that I've been considering rereading it ever since.
Anyway, strong recommend.