A morning paper for product designers
Today's thread

Model price wars are outpacing anyone's ability to evaluate quality

Willison documents GPT-6 Luna at $0.10/$0.50 and Sol at $2/$10 alongside Opus 5.5, while Lenny's blind taste test finds no single winner across emails, PRDs and frontend prototypes, and a separate Lenny's piece argues teams skip eval planning entirely. Cheaper tokens mean nothing if you can't tell which model is actually better for your workload, and most teams still aren't set up to know.

Reads9 picks · 8 min
01Simon Willison40 d

Claude Opus 5.5, GPT-6 Sol and Luna with half-price economics

The pricing compression across three new models changes what's economically viable for longer-context agentic workflows in your own apps.

Read on simonwillison.net
Try today

Run Lenny's blind taste test format on your own recent frontend prototyping task across Opus 5.5 and GPT-6 Sol before picking a default.

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