Claude Fable 5.1 is the best assistant we have scored: our tests put it #1 overall, with empathy and creative writing clearly ahead of GPT-6 Astra. It is not our recommended daily driver. Adaptive thinking is always on, so the average assistant query costs and waits much more than cheaper models—for a personal assistant, speed matters too. Outputs are text-watermarked (https://www.chatio.dev/blog/how-anthropic-and-google-watermark-text), so skip it for copywriting or consumer-facing text.