When comparing Emacs vs Visual Studio, the Slant community recommends Visual Studio for most people. In the question“What are the best third-party IDEs for Unity?” Visual Studio is ranked 3rd while Emacs is ranked 6th. The most important reason people chose Visual Studio is:
If a project type or a platform is available for C#, it's available in Visual Studio. Some IDEs and code editors may cover some project types, but Microsoft always starts with VS. If you work with a cross-platform technology like ASP.NET MVC, it matters less. If you work with Windows-only technologies like UWP or WPF, you have no choice really.
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 Official IDE developed by Microsoft
If a project type or a platform is available for C#, it's available in Visual Studio. Some IDEs and code editors may cover some project types, but Microsoft always starts with VS. If you work with a cross-platform technology like ASP.NET MVC, it matters less. If you work with Windows-only technologies like UWP or WPF, you have no choice really.
Pro Free Community edition
Community edition is almost Pro edition, with just a few exceptions. Unlike old Express editions, it supports plugins.
Pro Excellent and broad range of plugins
The plugin development ecosystem is very mature and covers a lot of use cases. For example, it is often easy to find a plugin which allows you to have the keybindings of your preferred editor.
Pro Supported by ReSharper and other plugins
Code productivity tools improve code editing experience greatly, provide static code analysis, refactorings, navigation etc. They are considered by many developers as essential.
Pro Supports every kind of .NET development, every project type
Pro Product backlog
In agile development teams one really needs features such as product backlogs where you can assign features to team mates and track their progress on them. VS provides a web based interface for you to track your team's complete progress on the project.
Pro Cloud storage
Your Visual Studio Online account gives you a place to store your code, backlog, and other project data with no servers to deploy, configure, or manage.
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 Slow
Visual Studio is very slow if you don't have a decent system, but even then it can still be slow. Once you get past the first few minutes of slowness, it runs fine, but this should not be acceptable for a professional-grade IDE. This can be caused by a multitude of factors, such as extensions.
Con Professional Pricing is a bit steep
The professional edition's pricing is endearing since it costs more than IntelliJ, however, you wouldn't need that if you're not developing for a enterprise.