When comparing Emacs vs Codiad, the Slant community recommends Emacs for most people. In the question“What are the best programming text editors?” Emacs is ranked 9th while Codiad is ranked 51st. The most important reason people chose Emacs is:
Emacs can be controlled entirely with the keyboard.
Specs
Question Ranking
Pros
Pro Keyboard-focused, mouse-free editing
Emacs can be controlled entirely with the keyboard.
Pro Total customizability
Customizations can be made to a wide range of Emacs' functions through a Lisp dialect (Emacs Lisp). A robust list of existing Lisp extensions include the practical (git integration, syntax highlighting, etc) to the utilitarian (calculators, calendars) to the sublime (chess, Eliza).
Pro It's also an IDE
You can debug, compile, manage files, integrate with version control systems, etc. All through the various plugins that can be installed.
Pro Works in terminal or as a GUI application
You can use Emacs' command line interface or graphical user interface.
Pro Self documenting
Emacs has extensive help support built-in as well as a tutorial accessed with C-h t.
Pro Free
Licensed under GNU GPL.
Pro Great documentation
With 30+ years of use the Emacs documentation is very thorough. There are also a lot of tutorials and guides written by third parties.
Pro Mini buffer
You can pass complicated arguments in the mini buffer.
Pro Ubiquity
Fully compliant GNU-emacs is available on many platforms, and they all understand .emacs configuration files.
Pro Rectangular cut and paste
Emacs can select rectangularly.
Pro Lisp customizations
With lisp customization, any behavior of Emacs can be changed. Update with pre-release patch can be also applied without recompiling the whole Emacs.
Pro Vi keybindings through Evil mode
Evil mode emulates vim behaviors within Emacs. It enables Vi users to move inside the Emacs universe.
Pro Visual selection and text objects with Evil
Evil is an extensible vi layer for Emacs. It provides Vim features like Visual selection and text objects.
Pro Support multi-line editing, multiple frame, powerful paren, crazy jumping style
Review the "Emacs Rocks" video.
Pro Provides org-mode
Advanced planning and publication which can start as a simple list.
Pro Has been widely used for a long time
Pro dabbrev-expand (Alt-/)
Dynamic word completion.
Pro Cross-platform
Works on Linux, Windows, Macintosh, BSD, and others.
Pro Enormous range of functionalities (way beyond simple "text editing")
Through its programmability, a very broad range of functionalities can be integrated in emacs, turning it even into a "single point of contact" with the underlying operating system.
Pro Integrates planning in your development process
You can jump straight from your org-mode files to programming tasks - and back - and build a seamless workflow.
Pro Helm plugin adds even more power to Emacs
Powerful commands, search, and more with the Helm plugin.
Pro GTK+ widgets support
Since version 25 you can run GTK widgets inside Emacs buffers. One of these is the WebKitGTK+, which allows the user to run a full-featured web browser inside Emacs with JavaScript and CSS support among other things.
Pro Open source
You can run Codiad on your server to allow you and your team to edit files.
Simplest to run may be using a Docker image like linuxserver/codiad.
Pro Easy to self-host: Only requires PHP
It only requires PHP 5+ and Nginx or Apache. No database is required. This makes it really easy to install on many servers include shared hosting.
Pro Multi-line edit
Allows to edit multiple things are once by having multiple cursors like Sublime Text.
Pro Has many easily installable plugins
Many plugins exist, from Terminal, Git to Collaboration and Emmet... Plugins can be installed by using the web interface, or by manually extracting files to the right directory.
Pro Simple and easily managable GUI
Cons
Con Learning curve is long
While it's better than it used to be, with most functions being possible through the menu, Emacs is still quite a bit different from your standard editor. You'll need to learn new keyboard shortcuts.
Con Sometimes the extensibility can distract you from your actual work
If I ever want to lose half a day, I'll start by tweaking my .spacemacs config file.
Con Chorded keyboard combinations can be baffling
For example, for navigation it uses the b, n, p, l keys. Which for some people may seem strange. But don't worry, you can change it.
Con A lot of jokes in this serious software
Con Using Emacs on a new machine without your .emacs file
Con Terminal runs as same user for everyone
No matter who is the logged in user, the Terminal plugin runs commands as the PHP user. This also affects the Git plugin in that there is a single SSH key for all users using your Codiad instance.
Con Full of small bugs
There are plenty of various issues and bug that may either be due to your setup and the UI will not report them, or due to bugs in the code; I'm including common plugins here as well (just naming a few: search files and in files may report nothing if it had an error, commands stderr not printed, marketplace not showing items, search in market place showing no results, Git escaping ( by \( in the commit message for no good reason...). Those are generally small but together it makes the product feel flawed.
Con Currently no search and replace in multiple files
There is a search in multiple files, and search & replace in current file, but not something to perform a search & replace in multiple files.
Con Terminal doesn't TTY
The terminal plugin for Codiad allows users to type some commands and see the outputs, but not interactive input is supported (i.e. stdin is closed). Meaning you cannot run Vim, Tmux or anything requiring user inputs.