Having both Atom and VS Code installed on recent hardware I can say VS Code definitely feels snappier in multiple aspects. It's hard to believe both editors share Electron roots.

And not to make this an X is better than Y comment, but the much better (in my experience) high-DPI handling with VS Code does the same. I wonder what exactly VS Code does to manage to be the only Electron based application that I've used that scales properly across multiple monitors at different DPIs.