From the perspective of a web app developer it's just so modern. The language of the interface takes all of the (admittedly subjective) best-practice lessons that the web has taught us over the years and embeds them directly in, and then lets you hack them apart however you wish -- simply. Code editing works without a thousand inconsistencies, and then you have things like embedding your terminal directly with ease (its trivial to create a tmux like environment), etc.

The limitations feel very few, and as someone who spent a LOT of time getting my Vim environment exactly as I wanted it, switching over to Atom was a breeze as I went through my .vimrc trying to match functionality; most of it was already there.

One thing I wish they would implement (and I'm sure it will come with time) is the ability to fully navigate the file tree with the keyboard, similar to NERDTree. All you can do right now is arrow up and down, after toggling over.

I've heard its like Emacs -- and now I know what people are talking about!

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.

None.

Atom's installer is a huge download, and the editor is much slower ... It also consumes much more memory and written in coffeescript. Takes a long time to start up ... just a few things on the top of my head.

It's a great initiative though so that's already a good point.

It offers a point and click interface for people that can't be fucked to learn how to set up a .vimrc