I’ve been testing every major frontier model release since the start of the year, and when Anthropic dropped Sonnet 5, I wanted more than a vibe check. I got tired of one-off tests I couldn’t repeat or compare over time, so I built something better: the How I AI Bench, a repeatable eval harness I constructed live using Claude Code while recording this episode. I ran Sonnet 5 blind against four other frontier models (Sonnet 4.6, Opus 4.8, GPT-5.5, and Gemini 3 Pro) across PRD quality, prototype generation, agentic task completion, and agent personality. The results were not what I expected. What you’ll learn: 1. What Anthropic claims Sonnet 5 improves over Sonnet 4.6, and where the benchmark data actually backs that up 2. How I built the How I AI Bench in under 45 minutes using Claude Code, starting from my own stored session history 3. Why I combined human vibe scoring (70%) with LLM as judge scoring (30%) instead of trusting either alone 4. How to set up a local HTML scoring page so you can rate AI outputs on gut feel and export those scores as JSON 5. Which model I recommend for PRDs, which for complex prototypes, and which for chatting with an agent daily — Brought to you by: Runway [https://runwayml.com/howIAI]—The creative AI platform for images, video and more Hyperagent [https://hyperagent.com/howiai]—Deploy fleets of agents that handle real work — In this episode, we cover: (00:00) Sonnet 5 is out (01:55) What Anthropic claims (04:02) Why I’m done with one-off vibe checks (05:05) Building the How I AI Bench live with Claude Code (07:42) The scoring system (10:43) Agent voice eval (11:57) Quick recap (13:58) Results: The How I AI index leaderboard (21:21) What I’m improving for the next run (22:16) Generating a Claire-weighted index (23:53) Model-by-task recommendations — Tools referenced: • Claude Sonnet 5: https://www.anthropic.com/news/claude-sonnet-5 [https://www.anthropic.com/news/claude-sonnet-5] • Claude Opus 4.8: https://www.anthropic.com/news/claude-opus-4-8 [https://www.anthropic.com/news/claude-opus-4-8] • GPT-5.5 (OpenAI): https://openai.com/index/introducing-gpt-5-5/ [https://openai.com/index/introducing-gpt-5-5/] • Gemini 3 Pro (Google DeepMind): https://deepmind.google/models/gemini/pro/ [https://deepmind.google/models/gemini/pro/] • Cursor: https://www.cursor.com/ [https://www.cursor.com/] — Other references: • SWE-bench Pro (agentic coding benchmark referenced): https://www.swebench.com/ [https://www.swebench.com/] — Where to find Claire Vo: ChatPRD: https://www.chatprd.ai/ [https://www.chatprd.ai/] Website: https://clairevo.com/ [https://clairevo.com/] LinkedIn: https://www.linkedin.com/in/clairevo/ [https://www.linkedin.com/in/clairevo/] X: https://x.com/clairevo [https://x.com/clairevo] — Production and marketing by https://penname.co/ [https://penname.co/]. For inquiries about sponsoring the podcast, email jordan@penname.co.