I don't think there's a bias here. I'd say my task is of somewhat high complexity. I'm using Claude to assist me in implementing exceptions in my programming language. It's a SICP chapter 5.4 level task. There are quite a few moving parts in this thing. Opus 4.6 once went around in circles for half an hour trying to trace my interpreter's evaluator. As a human, it's not an easy task for me to do either.

I think the problem just comes down to adaptive thinking allowing the model to choose how much effort it spends on things, a power which it promptly abuses to be as lazy as possible. CLAUDE_CODE_DISABLE_ADAPTIVE_THINKING=1 significantly improved Opus 4.6's behavior and the quality of its results. But then what do they do when they release 4.7?

https://code.claude.com/docs/en/model-config

> Opus 4.7 always uses adaptive reasoning.

> The fixed thinking budget mode and CLAUDE_CODE_DISABLE_ADAPTIVE_THINKING do not apply to it.