Early GPT-5.5 impressions - finally an OAI model that matches Claude at tool calls
Until yesterday, Opus/Sonnet were the only reliable options if you wanted to build a fast, long-running agent. GPT-5.4 was good, but thought too much, and was super slow. It also polluted the context with too many thinking tokens and so had degraded performance at long-running tasks.
Gemini models are... just weird at tool calling - they often get stuck in infinite loops.
GPT-5.5 costs slightly less than Opus across the tool calling loop, is just as fast, and just as good. I like its personality more - much less hedging (specially for things like financial analysis) and more to the point.
It's also much more broadly useful. Codex with GPT-5.4 was pretty good at code, but Opus was just better for general tasks. GPT-5.5 feels super competent across the board.
Really excited for this release. Makes the LLMs for AI-agent market competitive again!