I will switch to this if it is as good as Sublime Text, but with a more open API. Sublime Text's API is too restricted, and there's a ton of things I want in Sublime Text that IDEs have.. but I don't want a full-blown IDE.

Take the overall diff bar of most IDEs for example (Jetbrains, Netbeans, etc.). I want that in Sublime/Atom. There is a plug-in for Sublime to show diffs per line, but no way to manipulate the mini-map to show diffs at a glance.

http://blog.jetbrains.com/pycharm/files/2013/12/2.png

Edit:

See, this is inferior and what Sublime Text already has: http://atom.io/packages/git-diff

What's superior is a full-blown diff bar overview of the file.