Comment by embedding-shape

> that it’s just a magic bullet that makes the model work harder and achieve better results

"Ultra" is a harness feature, and has nothing to do with the model itself. If OpenAI wanted to, they could offer "Ultra" with any of the GPT models, although 5.6 supposedly been trained with this specific harness feature in mind. "max" is basically the top "work harder and achieve better results" parameter for the reasoning effort for the current models.

I had good success with it initially, until I discovered that OpenAI encrypts the prompts that the main model sends to the sub-agents (even in Codex, in local files you only see cipher text), then I completely dropped any experimentation of it as without introspection, it becomes basically useless for any real usage.