Sure, Sonnet 5 loses to Opus 4.8 on benchmarks.
But the real unlock isn't the model, it's the stack!
You mix them in Claude Code to merge frontier intelligence with practical efficiency.
Here is how to configure it:
> The Advisor: Let Fable 5 handle frontier-level reasoning and strategy.
> The Implementer: `Run /model set to Sonnet 5` for fast, cheap execution.
> The Workflow: Run `/effort set to Ultracode` to trigger dynamic workflows for complex tasks.
With this pairing, Fable becomes your superintelligent brain, and Sonnet becomes the hands rapidly typing the code 🧠