11.10Key Takeaway

There is no single best tool. Copilot excels at inline completion, Cursor at interactive iteration, and Claude Code at full-suite generation with autonomous execution -- with framework-native agents (Cypress cy.prompt(), Playwright Test Agents) as a fourth option when you live inside one framework, and autonomous agents like Devin adjacent to the QA workflow. The most effective engineers use the right tool for each task, often several in the same week.