I've been using Claude and Codex in tandem ($100 CC, $20 Codex), and have made heavy use of claude-co-commands [0] to make them talk. Outside of the last 1-2 weeks (which we now have confirmation YET AGAIN that Claude shits the fucking bed in the run-up to a new model release), I usually will put Claude on max + /plan to gin up a fever dream to implement. When the plan is presented, I tell it to /co-validate with Codex, which tends to fill in many implementation gaps. Claude then codes the amended plan and commits, then I have a Codex skill that reviews the commit for gaps, missed edge cases, incorrect implementation, missed optimizations, etc, and fix them. This had been working quite well up until the beginning of the month, Claude more or less got CTE, and after a week of that I swapped to $100 Codex, $20 CC plans. Now I'm using co-validation a lot less and just driving primarily via Codex. When Claude works, it provides some good collaborative insights and counter-points, but Codex at the very least is consistently predictable (for text-oriented, data-oriented stuff -- I don't use either for designing or implementing frontend / UI / etc).

As always, YMMV!

[0] https://github.com/SnakeO/claude-co-commands

Some variation of this is the way.

You should not get dependent on one black box. Companies will exploit that dependency.

My version of this is having CC Pro, Cursor Pro, and OpenCode (with $10 to Codex/GLM 5.1) --> total $50. My work doesn't stop if one of these is having overloaded servers, etc. And it's definitely useful to have them cross-checking each other's plans and work.

This more or less mimics a flow that I had fairly good results from -- but I'm unwilling to pay for both right now unless I had a client or employer willing to foot the bill.

Claude Code as "author" and a $20 Codex as reviewer/planner/tester has worked for me to squeeze better value out of the CC plan. But with the new $100 codex plan, and with the way Anthropic seemed to nerf their own $100 plan, I'm not doing this anymore.