In our evals for answering cybersecurity incident investigation questions and even autonomously doing the full investigation, gpt-5.2-codex with low reasoning was the clear winner over non-codex or higher reasoning. 2X+ faster, higher completion rates, etc.

It was generally smarter than pre-5.2 so strategically better, and codex likewise wrote better database queries than non-codex, and as it needs to iteratively hunt down the answer, didn't run out the clock by drowning in reasoning.

Video: https://media.ccc.de/v/39c3-breaking-bots-cheating-at-blue-t...

We'll be updating numbers on 5.3 and claude, but basically same thing there. Early, but we were surprised to see codex outperform opus here.