If there's no substantial difference in software development expertise then GPT-5 absolutely blows Opus out of the water due to being almost 10x cheaper.
Because if not, I'd still go with Opus + Claude Code. I'd rather be able to tell my employer, "this will cost you $200/month" than "this might cost you less than $200/month, but we really don't know because it's based on usage"
> Availability and access > GPT‑5 is starting to roll out today to all Plus, Pro, Team, and Free users, with access for Enterprise and Edu coming in one week. Pro, Plus, and Team users can also start coding with GPT‑5 in the Codex CLI (opens in a new window) by signing in with ChatGPT.