Well the main one would be if you already used Atom and didn't want to migrate to VSC.
The plan is to build upon the "hackable" nature of Atom and really run with it. It should be easy to customise it yourself however you want, the (lofty) ambition would be to think of it something like an Electron based version "Emacs" where anything you can think of writing or changing in Javascript (or anything that can be transpiled to it) can be reflected in the editor.