When comparing nnn vs Spacemacs, the Slant community recommends nnn for most people. In the question“What are the best file managers for UNIX-like systems?” nnn is ranked 1st while Spacemacs is ranked 23rd.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Superfast
Pro Rich set of plugins
Pro Extremely lightweight (120 kb)
Pro Unique navigate-as-you-type mode
Pro Awesome new features being added in every release
Pro Minimal configuration with sane defaults
Default options and navigation is simple to grasp.
Pro Has a great wiki
Pro Sessions
Save and resume sessions.
Pro Supports cd-on-quit
Allows for quick switching between nnn and the terminal.
Pro Previews
The file manager has recently added support for preview hovered files using various methods.
Pro Integrates with the desktop environment and opens files in the default applications
Pro Reasonably well-documented
However, it requires some prior knowledge of inner workings of Linux and there are no tutorials (yet). NNN author is making up for this by actively responding to GitHub issues.
Pro Customizable icons and colors
Pro Preconfigured emacs distro
Spacemacs is just a well-configured Emacs distribution with community-sourced best in class plugins and layers selected to take the setup pain out of Emacs. Evil mode gives the Vim bindings and modes for fast editing, while Helm makes everything discoverable to make learning to be more productive simple and unintrusive.
Pro VIM Keybindings with EMACS ecosystem
EMACS ecosystem and language support is best in show. The EMACS is a great IDE that was in search of a good text editor. Spacemacs makes EMACS have a good text editor.
Cons
Con CLI, default interface very simplified (supports mouse)
Con Emacs is slow
Emacs is single threaded which means that if you enable all the great features you might be used to from Vim, it will run noticeably slower which can be quite frustrating at times. There are efforts at a concurrent Emacs, but they don't seem to be going anywhere.