Vibe Check Live: GPT-5.3 Codex vs. Opus 4.6—INSANE new models from @OpenAI and @AnthropicAI . We’ve been testing both hands-on for over a week. Let''s go through our head-to-head take! Dan Shipper 📧 Verified account @danshipper Vibe Check live: GPT-5.3 Codex vs. Opus 4.6—INSANE new models from OpenAI and Anthropic We’ve been testing both hands-on for over a week. We’ll go through our head-to-head take!