OpenAI Cancelled GPT-6.1 Astra. Here's What Shipped Instead

The day before OpenAI launched its always-on agents, word got out that it had cancelled the next version of the model under them: GPT-6.1 Astra failed to meet OpenAI's own safety and alignment standards in testing. Between September 22 and 30, three other new models came out: Anthropic's Claude Opus 5.5, OpenAI's GPT-6.1 Sol and Google's Gemini 4 Argon. What each one can do, where you can use it, how to read the charts they launched with, the limits each company put around its model, and four checks you can run on any model before you trust it.