For example, Github only autocompletes based on what file you have opened in the current editor's tab. Windsurf indexes your entire code base and seems able to autocomplete based on what other files you have in your project. Autocomplete also spans across multiple lines and open tabs.
Windsurf's agentic tool (Cascade) can run terminal commands and read the output without opening a terminal like copilot. It can undo the agent's actions easier than Copilot. Though I think Cursor is superior in that regard, it can undo multiple checkpoints.
Still evaluating Windsurf but it, Cursor, and Claude Code are all more sophisticated than Github copilot at the moment. I'm sure copilot will catchup but by that time the other tools may have already iterated ahead.