This is really cool stuff. Editing notebooks in the browser is pretty good, but it can't (yet) match the experience of a well configured (and extended) text editor.
I've been using vscode with the jupyter extension (https://github.com/DonJayamanne/vscodeJupyter) and it's exactly what you describe, experience of a good text editor and the visual notebook workflow.
Neat, I'll give that a shot. Does it handle all kernels?
It doesn't appear to. Helpfully, Hydrogen [0] for Atom was designed to be entirely language agnostic.