I'm evaluating AI coding assistants for my team. We're working on a legacy Python (3.7) codebase with a lot of old Flask routes and SQLAlchemy models. I tested GitHub Copilot (Individual) and Cline (beta) on the same three tasks.
Task 1 was adding a new API endpoint following existing patterns. Copilot gave me the full function skeleton instantly. Cline asked for more context about the database schema first, which slowed me down a bit, but its suggestion was more aligned with our error handling.
Task 2 was refactoring a messy function. Copilot's inline suggestions were helpful for small changes. For the bigger refactor, Cline's chat interface felt better. I could explain the goal ("split this into three functions, keep the same outputs").
Task 3 was writing a database migration script. Both struggled with the specifics of our old migration framework. Copilot generated code with methods we don't use. Cline at least admitted it was unsure and gave a simpler, more correct example.
My quick take: Copilot is faster for predictable, pattern-matching work. Cline felt more cautious and better for tasks where you need to discuss the approach. For our messy legacy code, that cautiousness was sometimes an advantage. Has anyone else compared them on older code? I'm curious about long-term maintainability, not just speed.