gpt-5-6-luna vs gpt-full on rewrite edit: 2.1 quality points, 3.4× price.

Both measured on the same held-out rewrite-edit suite: gpt-5-6-luna at 0.933 and $0.2974, gpt-full at 0.912 and $1.02 per thousand requests. Both figures come from the same held-out rewrite edit suite, 100 scored items, measured the same way — so the comparison is like for like.

Both were run against the same held-out items on the same day, so the gap is a property of the models rather than of the test. A 3.4× price difference at this quality distance is the whole decision.

Someone is paying the difference. If that is you, the question worth asking is which of these two numbers your workload actually needs — and this is the measurement that answers it.

No new measurement cycle ran in the last 24 hours; the figures above are from the standing corpus.

The current numbers live on the measured answers; the method is public.