When comparing Org mode for Emacs vs Turtl, the Slant community recommends Turtl for most people. In the question“What are the best note taking apps for UNIX-like systems?” Turtl is ranked 1st while Org mode for Emacs is ranked 14th. The most important reason people chose Turtl is:
Turtl has applications for all the major operating systems, as well as Android. In addition, there are extensions available for Firefox and Chrome that cooperate with the downloadable applications.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Can be as simple or as complex as you want
Org mode started out as a simple outlining/note taking app. Then each outline heading can optionally be a TODO list item. And if you desire, you can add SCHEDULE and DEADLINE dates. (Schedule being the date you'd like to start the item.) You can customize the TODO states to add things like DELEGATED, WAITING, BLOCKED, etc.
Pro Libre/open source
Pro Cross platform
Emacs runs on all platforms, Windows, Linux, OSX, even Android and IOS

Pro Exports data to PDF, LaTeX, HMTL and other
You can even build presentation or blog from your data

Pro Supports tables with formules (quite powerful!)
Pro Plain text data storage
Future-proof.
Pro Inline image displaying
Pro Free but copyrighted
Pro Fast interaction
Once muscle-memory sets in, can be much faster to use than a point & click program.
Pro Uses Emacs
Pro All apps
Pro Multiple Platforms (Windows, Linux, macOS, Android, Firefox, Chrome)
Turtl has applications for all the major operating systems, as well as Android. In addition, there are extensions available for Firefox and Chrome that cooperate with the downloadable applications.
Pro Open source
The app is licensed under GPLv3 making it open source. This means that anyone can use the code and contribute. This also makes it easy to use on one's own server or for company solutions.
Pro Good security
After assigning a password to your account in Turtl, a key is created to encrypt the entire account. No data is stored on their servers meaning they have no access to unencrypted content. This is a huge leg up when comparing to other Evernote alternatives.
Cons
Con Obtuse documentation
The documentation assumes a level of understanding of basic Emacs usage that not all users may have.
Con Complicated to get started
Con Difficult to use as a database
For example, if you need to quickly populate client details on quotes, unfortunately its easier to find, copy & paste.
Con Not suitable for normal users
Not even a majority of software developers can be bothered to use Emacs (or VI, for that matter).
Con PDF export can be difficult
Latex assumes you're a (compliant) student, have to do a lot of research to get what you want out of it.
Con Uses Emacs (for those who prefer vi, menus, etc.)
Con No iOS app
While many other operating systems have a client, iOS does not have one yet (though it is planned).
Con No image embedding
Instead of image embeddings, there's a sort of poor man's substitute: image + description. If you add an image, you can create a description of any size and with all the formatting features. It can be used instead of image embedding but much more limited: only one image and only at the very top.
Con Internet dependent
Requires Internet connection to initiate offline mode, loses access to notes without Internet or server.
