TL;DR: Six months ago I published a Copilot-specific model guide. Almost every name on it has since been superseded. This mid-year update widens the lens beyond GitHub Copilot to every environment — Cursor, Codex, Windsurf/Devin, Claude Code, or a raw API — and gives each current model the same exhaustive best for / when to use / trade-offs / pro tip treatment. It covers the closed-source frontier (Anthropic, OpenAI, Google, xAI) and the open-weight surge (GLM, DeepSeek, Kimi, Qwen, MiniMax, Nemotron, Mistral) that has, this year, become genuinely production-grade.
Generated AI image by Google Gemini Nano Banana
Introduction
Back in January I wrote a guide to GitHub Copilot’s model picker — GPT-5, the early Claude 4 lineup, Gemini previews, and which to reach for when. That post aged in weeks, which six months on feels like the whole point of writing about this space.
Since then: Anthropic shipped Sonnet 5 and Opus 4.8, launched a new top tier (Fable 5), and had to pull that top model off the market for three weeks under a US export-control order before restoring it. OpenAI iterated through GPT-5.4, 5.5, and the GPT-5.6 “Sol / Terra / Luna” family, and merged its Codex and general-purpose stacks into one model. Google shipped Gemini 3.5 Flash but scrapped and rebuilt its next flagship from scratch. xAI turned Grok into a coding-first model co-trained with Cursor. And a cluster of open-weight labs — Z.ai’s GLM, DeepSeek, Moonshot’s Kimi, Alibaba’s Qwen, MiniMax, and NVIDIA’s Nemotron — closed the gap on the frontier to single benchmark digits while running at a fraction of the cost.
This time the post is not Copilot-specific. If you’re in Cursor, Codex, Windsurf, Claude Code, or straight through an API, the same models and trade-offs apply — only the interface changes. The discipline is the same as January: match the model to the task, not the task to whatever’s newest. There are just a lot more models now.