Zvi Mowshowitz's Fable 5.1 capabilities review: Terminal-Bench-Science jumps 24.7% to 52.6%, but users report 3x token burn

Don't Worry About the Vase (Zvi Mowshowitz)·high signalXBlueskyLinkedInCopy link

Zvi published his capabilities review of Claude Mythos 5.1 and Fable 5.1 on September 5, separate from his earlier system-card post. He pulls out Terminal-Bench-Science rising from 24.7% to 52.6%, CursorBench 3.2 at 73.4% vs 70.5%, OSWorld 2.0 at 78% partial/42% strict, HLE at 60.9%, a cache-read price drop from $1 to $0.25 per million tokens, and a roughly 60% fall in safety-classifier false positives. The catch for builders on subscriptions: multiple users report Fable 5.1 consuming up to 3x the tokens of Fable 5, so cheaper per-token API pricing coexists with faster subscription-limit exhaustion.