Anthropic users say Opus 5 is best for complex agents, while Sonnet 5 fits routine coding
dr_cintas · x · 2026-07-26
The post says that after 24 hours with Opus 5, the real question is not whether to raise effort, but which model to switch to for each task.
It recommends:
- Sonnet 5 for everyday coding, drafts, and quick edits
- Opus 5 for complex agentic coding, enterprise work, and long-horizon tasks
- Fable 5 for maximum capability and agents that run for days
It then frames effort as the key lever:
- High-effort Sonnet can become expensive without changing the underlying generalist nature
- Low-effort Opus can already perform well at much lower token and latency cost
- Even low-effort Fable may outperform the previous generation’s high-effort mode, while max effort is where its long-horizon advantage appears
The takeaway is to match task, model, and effort level instead of blindly turning every setting up to maximum.
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