Provided such a Opus 5 performs on par with Fable 5 and GPT 5.6 Sol.
Otherwise I am not interested.
Supposedly Fable 5.1 is in the later stages of the release pipeline, maybe it takes back the crown from OpenAI, who are now rumored to launch GPT 6 in August.
My Fable weekly limit is at 15% used already, 5.6 Sol at 3% used. And this is with the Max 20x plan compared to Codex 5x.
I don't work on the same tasks to compare them objectively, but GPT 5.6 on xhigh seems much cheaper. Essentially unlimited usage.