The issue isn't whether it's fine, it's that both Fable 5 and Opus 5 are worse to use for the job of programming than Codex-5.6-Sol in my experience. I am directly comparing these top tier models every week in my work, and many friends have left Claude in favor of Codex recently because of Claude's poor model quality.

One thing I do like about Claude is that the normal (non-Code) chat interface supports MCP, whereas ChatGPT basically does not.