The Two Best AI Models/Enemies Just Got Released Simultaneously

The two models that you will hear discussed for at least the next two months - Claude Opus 4.6 and GPT 5.3 Codex - just got released within 26 mins or each other. The full breakdown of around 250 pages of reports, with just the most interest moments, from the battle of which is best, Claude personhood, the surprising misbehaviour of Opus 4.6, and much more

https://assemblyai.com/aiexplained

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Chapters:
00:00 - Introduction
00:54 - Self-improvement?
02:44 - Knowledge Work
05:30 - Overly agentic behaviour
09:12 - Who Shouldn’t Use Claude Opus
11:39 - Step-change?
15:09 - Claude’s ‘Personhood’

Hassabis Roadmap: https://www.patreon.com/posts/hassabis-roadmap-149750869

Release of Opus 4.6: https://www.anthropic.com/news/claude-opus-4-6
212 Page System Card: https://www-cdn.anthropic.com/0dd865075ad3132672ee0ab40b05a53f14cf5288.pdf
Claude Code Tip: https://x.com/bcherny/status/2019475897691124107


GPT Codex 5.3: https://openai.com/index/introducing-gpt-5-3-codex/

System Card: https://openai.com/index/gpt-5-3-codex-system-card/

Browse Comp: https://arxiv.org/pdf/2504.12516v1
Finance Agent: https://www.vals.ai/benchmarks/finance_agent
Terminal Bench 2: https://arxiv.org/pdf/2601.11868
Vending Bench: https://andonlabs.com/blog/opus-4-6-vending-bench

My X post: https://x.com/AIExplainedYT/status/2016851303436095647

Anthropic Apology: https://x.com/ch402/status/2014066134194995256/photo/1

Altman rebuttal: https://x.com/sama/status/2019139174339928189
https://x.com/sama/status/2019140276246442089

4% of GitHub: https://x.com/dylan522p/status/2019490550911766763



Non-hype Newsletter: https://signaltonoise.beehiiv.com/

Podcast: https://aiexplainedopodcast.buzzsprout.com/