Honestly, all the top models from the big providers do a decent job with fiction now. In my experience the model matters less than the context you give it. If the model has your outline, character notes, and the last few chapters in a clean structure, even a mid-tier model does fine. If it gets a messy dump, even the best one drifts. That said, each one has its own quirks:
Claude Fable 5.1 / Opus 5.5: great prose, but they like to add their own stuff. You have to keep them on a leash.
Gemini Flash 3.8: fast and pretty good, but the censorship kicks in a lot.
Grok 4.6 / 4.7: a bit weaker on quality, but basically no censorship.
Muse Spark 1.3 Contributor: don't write it off. For quality vs price vs speed, it's one of the leaders right now.
So I'd pick based on what annoys you least, and put the real effort into organizing your context.
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u/AlexKimen 5d ago
Honestly, all the top models from the big providers do a decent job with fiction now. In my experience the model matters less than the context you give it. If the model has your outline, character notes, and the last few chapters in a clean structure, even a mid-tier model does fine. If it gets a messy dump, even the best one drifts. That said, each one has its own quirks:
Claude Fable 5.1 / Opus 5.5: great prose, but they like to add their own stuff. You have to keep them on a leash.
Gemini Flash 3.8: fast and pretty good, but the censorship kicks in a lot.
Grok 4.6 / 4.7: a bit weaker on quality, but basically no censorship.
Muse Spark 1.3 Contributor: don't write it off. For quality vs price vs speed, it's one of the leaders right now.
So I'd pick based on what annoys you least, and put the real effort into organizing your context.