I bought topmost tier and like it over other options in the book writing space. Tried all features except deep research. I own Vellum, Atticus, KDPSpy and Publisher Rocket already. So this is the perfect missing piece. What I especially like is not having to choose the LLM model and grapple with credit usage versus quality dilemma each time. Because hello, I want a good book and the software is supposed to do the choosing. Also, I like not paying credits per chapter because that creates another dilemma - conserve credits or not. And how do you even decide how many chapters are right for the book. That's for the software to decide. The credits are calculated on the number of words chosen for each book. I mostly write in the 30K and 40K words space. So the credit calculation method makes sense. Basically, the credit usage decision-making friction with Aivolut is zero. The UI is intuitive, credit calculation makes sense, many features are free, you can write many, many books with 2000 credits in Aivolut but you can't do the same with double the amount of credits elsewhere. If you kissed a lot of frogs, this may well be your prince. I usually buy LTDs and forget about them. This one was dismantled at once and very happy for it. The children's books need to have text superimposed on the illustration. But that's a technical tweak easily doable. As a non-fiction author who has written books pre and post AI, Aivolut took me by surprise on how it addresses a topic, builds the flow and makes content a page turner. If you really know how to write and not write a book, Aivolut will meet your standard. If you don't know how to write a book, well, now you don't need to know. Aivolut does it for you - books that you yourself want to read. And therefore, your target readers will do the same.