My monthly subscription for Claude is up in a week, is there any compelling reason to switch to Codex (for coding/bug fixing of low/medium difficulty apps)? Or is it pretty much a wash at this point?
One main thing is to de-couple the repos from specific agents e.g. use .mcp.json instead of "claude plugins", use AGENTS.md (and symlink to CLAUDE.md) and so on.
I love this because I have absolutely 0 loyalty to any of these companies and once Anthropic nerfs I just switch to OpenAI, then I can switch to Google and so on. Whichever works best.
But the real issue I ran into wasn't which model is better. It's that every time I switched, I lost weeks of accumulated context. The AI didn't know my project's conventions anymore, didn't remember the architecture decisions, didn't know what was tried and rejected.
What helped me was separating the project context from the tool. Keep the conventions, rules, and decisions in plain files in the repo. Both Claude Code and Codex can read them at session start. Then the question becomes "which model is sharper this week" instead of "can I afford to lose my context."
The answer to your question: it's mostly a wash on capability. The real cost of switching is the context you don't realize you're rebuilding.
...at least for my account, the speed mode is 1.5x the speed at 2x the usage