Recs.
Updated
A "next generation" Vim effort. Major overhaul to support more powerful plugins and better integration with tools such as IDEs.
SpecsUpdate
Pros
Pro Better integration with external tools
The core text editor is "headless", ie detached from the user-interface, so other programs can hook into it. This enables better integration with IDEs and browsers, where "Vim mode" has typically been a poor substitute because it was a partial rewrite, or a partial port at best. One of the advantages of Vim has always been ubiquity and Neovim makes it even more ubiquitous.
Pro TrueColor support in Terminal
While you have been able to use truecolor color schemes with vim for a long time when using gvim, terminal users where limited to the fallback 256 and 16 color palettes. Neovim lifts this limitation, making it potentially much easier on the eyes as a result.
Cons
Con Consume brain energy for editing that should be used for logic
Text editing in vim can be great once you've learned it, but it requires thinking about combination of commands. In other editors, you don't have to think about how to delete this part of code. You just think about how to implement a feature, what is a good design for this code. Even after you get used to using vim, it still requires your brain for editing.
Con Requires Brain Mode Switching
When editing in vim, you have you use the vim keys; when editing in every other window on your PC, or in Word or Excel or other application, you need to use the standard system key combinations. Learning the vim combinations can actually make you SLOWER at everything else.
Recommendations
Comments
Flagged Pros + Cons
Pro Work in TUI (Text User Interface)
Neovim can work on terminal, on a remote server over ssh.
Pro Modern code base
As a refactor over Vim, Neovim has greatly improved its code base. For example, some functionality is handled by libuv, the same code base that powers Node.js.
Out of Date Pros + Cons
Con No stable release yet
Neovim is as of yet in an unstable point in it's development. There is no stable release and using neovim for the moment should be done with caution as many features may change in the future.