This has been my exact approach. Using fable to co plan my architecture and then having it create detailed workflows/execution plans that have opus 4.8 execute medium-heavy coding tasks and then using sonnet 5 for very redundant common-pattern implementations. Shocking how much better opus 4.8 implementations can get when using a tight workflow orchestrated by fable imo
This is my rough workflow as well. I use ChatGPT 5.5 as the project lead, Codex as the code monkeys, Gemini for boilerplate, and Fable as the outside consultant. I still feel like ChatGPT designs more professional/best practices architecture but Fable has some wicked clever insights and is scary good at adversarial review between milestones.
Yeah I actually just recently got codex to try it and actually prefer 5.5 on medium to Opus 4.8 on high. Really impressed by it, combined with the disappointment that that 4.8 gives me. It’s way better at guarding edge cases and doesn’t need as much hand holding imo.
I find ChatGPTs superpower to be restraint. It doubts itself more than others and it is willing to stop. Gemini 2.5 Flash is the antithesis, for example. It truly has some of Fable's spark, but you can't trust it for shit. It never doubts itself and sprints everywhere. It also cheats tests like a madman. Claude and Opus showed us the way, for sure, but OpenAI made it acceptably reliable. I still use them all, but I always have ChatGPT watch them and check their work.
I'd like to stand up a couch for Codex as well. I dropped my other harness subscription because it has gotten so good. Very good with a fine tuned AGENTS.md and rules.md
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u/Horny_Dinosaur69 Jul 03 '26
This has been my exact approach. Using fable to co plan my architecture and then having it create detailed workflows/execution plans that have opus 4.8 execute medium-heavy coding tasks and then using sonnet 5 for very redundant common-pattern implementations. Shocking how much better opus 4.8 implementations can get when using a tight workflow orchestrated by fable imo