I’m writing my first sci-fi novel, and I’m using it for two main things. One, as a basic sanity check for the story, pacing, internal consistency, character development, etc, and basic copy editing. I’ve also used it to generate images for settings to go in the lore bible, so I can pin down what I see in my head into something tangible that I won’t forget. This isn’t the only step, I have human beta readers to double check the LLM, but it often tells me easily verifiable things, and it is often right, (for instance, this sentence reads funny), so it definitely adds value in that sense. Subjective things are a bit harder to trust, but that can be the same thing with subjective feedback from humans too, though of course the difference is that the LLM isn’t going to buy my book, whether or not it loves it.