Claude Code is a CLI tool which means it can do complete projects in a single command. Also has fantastic tools for scaffolding and harnessing the code. You can define everything from your coding style to specific instructions for designing frontpages, integrating payments, etc.
Implementation differences do matter. I haven't found Copilot to have as many issues as people say it does, but they are there. Their Gemini implementation is unusable, for example, and it's not because of the underlying models. They work fine in other harnesses.