Background processes don't block the main thread, the extension points are better thought out and the development experience in working on extensions is a LOT better, js/coffee are better languages than vimL, and display is not limited to a fixed grid of text cells.
The downsides are that it's comparatively slow. The vim keybinding emulation isn't great but I can now use it without getting frustrated using ^[ to get back to normal mode.
I still use Vim for most things but I do Clojure/Clojurescript in Emacs evil-mode, and Typescript in Atom.
You should check out Neovim. The native scripting language is Lua, and it's a fork of the vim codebase so still fast and commands all work identically. It's still early, but I am monitoring (and supporting) the project closely.
The downsides are that it's comparatively slow. The vim keybinding emulation isn't great but I can now use it without getting frustrated using ^[ to get back to normal mode.
I still use Vim for most things but I do Clojure/Clojurescript in Emacs evil-mode, and Typescript in Atom.