Yes, it's been quietly nerfed
Many report Opus 5.5 and Fable suddenly making basic mistakes since early November, blaming quantization, A/B tests, or compute shifted to training the next model, and call silent changes anti-consumer or fraud.
Show me evals, not vibes
Skeptics note trackers like livenerf and nerf-bench show no drop, harness and Claude Code updates can mimic model changes, and human bias makes normal variance look like degradation.
Go local or open weights
A large faction argues self-hosted open models like Qwen 3.8 Flash Next give consistency you control, while others counter they are still far behind frontier models and the hardware is costly.