Fable 5.1 vs Fable 5 vs GPT-6 Astra: Reactions on Cost, Coding & Benchmarks

https://arena.ai/agent Early reactions on Anthropic's Fable 5.1 release — what actually changed, whether it's worth the price, and how it stacks up against the competition. 00:00 – Fable 5 vs 5.1 00:47 – The clearest gains: deeper coding capability 00:55 – The cost question: is Fable just burning tokens? 01:05 – Headline pricing, cache-read cost cuts, and why agentic runs still add up 02:18 – When Fable is worth using over a cheaper model 03:15 – Is this a big win for Anthropic, or are open models catching up? 04:06 – Open source vs proprietary — and how fast others closed the gap on Fable 5 05:28 – Is the pace of progress actually accelerating? 06:54 – First reaction to GPT-6 Astra vs Fable #arenaai #anthropic #llm