Here’s how I decide what to use:
ChatGPT – journaling, talking, planning.
Codex – framework and middleware-layer coding.
Claude Code – logic and application-level coding.
Anthropic models via OpenRouter + Cline – when the task is error-prone, tedious, or needs high fidelity; lower error rate in my experience, though pricier.
Cursor Agents – multi-file integration, boilerplate, and forking tasks.
Each fills a different slot in the workflow, so “best” depends on what kind of coding you’re doing.