Opus 5 Struggles in Complex Tasks While Fable Shows Deeper Reasoning

doodlestein · x · 2026-07-27

A developer observed in hands-on testing that Opus 5 underperforms in complex scenarios compared to Fable. While Opus 5 can self-reflect by listing its own mistakes during a session, Fable avoids these errors altogether by thinking more thoroughly before taking action. Even after adjusting for context rot, Fable maintains a meaningful edge in tricky situations.

Related event: Devs Test Opus 5: Strong Coding but Hard to Steer, Lags Fable in Complex Tasks(7 posts)→

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