I agree with this and actually Claude Code agrees with it too. I've had Codex cli (gpt-5-codex high) and claude code 4.5 sonnet (and sometimes opus 4.1) do the same lengthier task with the same prompt in cloned folders about 10x now and then I ask them to review the work in the other folder and determine who did the best job.
100% of the time Codex has done a far better job according to both Codex and Claude Code when reviewing. Meeting all the requirements where Claude would leave things out, do them lazily or badly and lose track overall.
Codex high just feels much smarter and more capable than Claude currently and even though it's quite a bit slower, it's work that I don't have to go over again and again to get it to the standards I want.
I share your observations. It's strange to see Anthropic loosing so much ground so fast - they seemed to be the first to crack long-horizon agentic tasks via what I can only assume is an extremely exotic RL process.
Now, I will concede that for non-coding long-horizon tasks, GPT-5 is marginally worse than Sonnet 4.5 in my own scaffolds. But GPT-5 is cheaper, and Sonnet 4.5 is about 2 months newer. However, for coding in a CLI context, GPT-5-Codex is night-and-day better. I don't know how they did it.
Every since 4.5, I can't get Claude to do anything that takes a while
4.0 would chug a long for 40 mins. 4.5 refuses and straight up says the scope is too big sometimes.
My theory is anthropic is super compute constrained and even though 4.5 is smarter, the usage limits and it's obsession with rushing to finish was put in mainly to save their servers compute.
100% of the time Codex has done a far better job according to both Codex and Claude Code when reviewing. Meeting all the requirements where Claude would leave things out, do them lazily or badly and lose track overall.
Codex high just feels much smarter and more capable than Claude currently and even though it's quite a bit slower, it's work that I don't have to go over again and again to get it to the standards I want.