When comparing Emacs vs MWeb, the Slant community recommends Emacs for most people. In the question“What are the best Markdown editors for OS X?” Emacs is ranked 13th while MWeb is ranked 16th. The most important reason people chose Emacs is:
Emacs can be controlled entirely with the keyboard.
Ranked in these QuestionsQuestion Ranking
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.
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.
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.
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
Pro Excellent support of LaTeX equations
Math-heavy note takers, look no further. Mweb even supports the basic LaTeX equation labeling and referencing, which you cannot find in any other markdown editor as of early 2018. Library management is another major plus.
Quick insert and editing of tables.
Pro Comes with an iOS app with iCloud sync
Once you are done editing your note on your mac, it's immediately available in your iOS devices, great for checkup anytime as you go.
Pro Small but powerful
It has file tree, can post article, can upload pictures, can render in pretty preview themes, and is small and fast.
Pro Supports publishing to popular web platforms
MWeb can publish Markdown files to various web platforms including (but not limited to) Wordpress, Metaweblog, Evernote, Blogger and Tumblr.
Pro Syntax highlighting in fenced code blocks
MWeb has syntax highlighting for some popular programming languages inside fenced code blocks.
Pro Supports publishing a static blog on FTP
Possible to manage your self-hosted static blog with your own css
Pro There's a free version, Mweb lite, on Mac OS and iOS
Pro Supports both its own database and external folders
So you can have a side project stored on its database, and your current notes on external folder, with simple files, that could be share with other apps.
Pro Drag & drop or paste photos to the editor and display
Supports adding pictures to a Markdown file either through drag-and-drop or by pasting it.
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 Indie app, possible to be abandoned at anytime
If you like the app, please buy it to make it sustainable.
Con No free version
MWeb costs $14.99 and is available on the Mac App Store. There's a free trial available but it's only for 14 days which may not be enough to make a good evaluation of the software before buying.