The comparison between harnesses is very nice. Interesting to see that using a different harness can bump the performance of the model as much as a new version (e.g., GPT 5.5+Codex ~= GPT 5.6+Terminus, at lower cost)
That’s a nice discussion. Some people say that with current model capabilities, the real differentiator is the harness. What are the best harnesses you guys are using?