When comparing ShiftEdit vs Codiad, the Slant community recommends ShiftEdit for most people. In the question“What are the best cloud IDEs?” ShiftEdit is ranked 7th while Codiad is ranked 21st.
Ranked in these QuestionsQuestion Ranking
Pros

Pro Low cost, high quality

Pro Revision control
Pro Syntax checking
Highlights syntax errors and automatically fix some errors
Pro Supports multiple file access points
Access files from FTP, SFTP, WebDAV, Dropbox, Google Drive or Amazon S3
Pro Supports autocomplete
Code completion for HTML tags, CSS and PHP code assist
Pro SSH support
Allows connecting directly to a server and run commands on that server.

Pro Good Customer Support
Help requests get answered quickly and successfully.
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 Expensive
Con Not user friendly
Con Non free/libre (proprietary)
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.
Con Demo only lasts 30min
