It's indeed a nice editor, but one main issue I have with it is that it doesn't detect the language of the file based on content, but solely on the file extension.
When working on websites you have your files like .js .html .css .php etc etc, but when working on system tools and scripts, a lot of these files lack the file extension and instead just defines the #! at the top of the file.
It doesn't even seem to be a way to manually specify that my file is of X language in the editor. According to the devs on their IRC channel, a feature like this isn't on the roadmap any time soon.
It's very unfortunate, but without this feature it's more hassle for me to work with it than with ST, or Vim.
Brackets is great if you are doing HTML/CSS/JS. But if you are doing other languages or using it as a normal text editor, Sublime Text is much more flexible and powerful. ST also handles large files better than Brackets.io or Atom.io as both of those use Chromium/Webkit as their editor.