I really like that I can edit my editor. A few times, I've disliked how something looked or wanted to add a feature. So I tweaked the stylesheet, or wrote an Atom plugin.

There's a beautiful poetry to being able to do web dev inside a web application.

I still have Sublime text for when I need to view/edit files with tens of thousands of lines, since Atom chokes on large files, but otherwise I have zero regrets :) I'm as productive in Atom, and it's a more pleasant experience.