First impressions: GPT 5.4 + GPT 5.3 codex spark!
After brew upgrade (and GPT 5.4 announcement last night) I was excited to see what was up. Interesting. Try 1 I did one minor feature using planning mode (gpt-5.4 high) and implemented it using gpt-5.3 codex spark. Codex spark is backed by super-fast Cerebras megachips, so I was optimistic about the speed (if not quality). Observations: REALLY fast (couple of seconds to implement something that was couple of hundred lines long) Bit stupid, or literal? It did not run unit tests by default Unit tests had an error, which it fixed It had used 62% of its context by this time(!) - seems like order of magnitude less context than 5.3 Codex Try 2 Without planning mode, on high, I asked it to refactor logging in the app I am working on. It actually did what was asked for, but again did not run tests as I did not specifically ask for it to run them too. The outcome was also pretty ugly as it did not look at the API surface of the logging library (or know it), so I had to send gpt-5.4 after it to clean up. ...