Sonnet 5.5, Opus 5.5 and GPT-6 Luna: The Cheap Tier Got Serious
· 6 min read
Three releases landed in one week: Opus 5.5 and GPT-6 Sol/Luna arrived in GitHub Copilot on September 22, and Sonnet 5.5 followed on September 28. I don't think the top end is the story. The story is cost: the cheap tiers now compete with last month's premium models. Every benchmark number below is vendor-reported, so read it as a claim, not a measurement.