Personally, I find vim's modal editing to be very efficient. When starting from a clean slate, it doesn't really matter much -- but when changing/editing existing text/code, I find it feels much more natural. It also works well without using the mouse, which is important to me because of carpal tunnel syndrome (and also helps when working without a proper mouse, such as on laptops).

I've only toyed with emacs, but based on that, I don't think emacs' idea of keyboard "chords" is as good a fit as vi(m). With standard keybindings, it also puts a strain on my wrists.

Modal editing and the "edit language"[1] (verbs, nouns, modifiers (and motions), like dw=delete word, dd/dl=delete line, d$=delete from cursor to end-of-line, dG (delete to endo-of-file, where gg/G is motion for moving to top/bottom of file respectively), ciw()P=change inner word (cut word under cursor to buffer), add "()", escape out of insert mode, paste word between "()"). These look cryptic, but quickly starts to feel quite natural and intuitive.

My impression is that Emacs' Evil-mode has evolved quite a lot lately, and allows one to combine the best of both: a much better programming language (scheme dialect) for customization, with modal editing and vi(m) key bindings. But I've yet to play with it.

If you don't mind using the mouse, you might also want to look at ACME[2] - it's a bit more exotic, and unfortunately hasn't gotten as much support as VIM/Emacs.

The creator of Vim, Mjolnar, has a great video on "7 Habits For Effective Text Editing 2.0":

https://www.youtube.com/watch?v=p6K4iIMlouI

I think the idea is very powerful: aim for incremental improvement in your workflow. You don't have to use vim to do that, but you certainly can use vim for that. Another editor that might be worth a look if you're not already familiar with vim, is: https://github.com/mawww/kakoune

The main argument for Neovim/vim/Emacs over other "smaller" editors would be the plugin eco-system. I have a theory though, that beginners tend to start out with a lot of plugins, and then gradually trim down, as they realize the power that lies within the editor itself.

Still, for vim, you will probably want a plugin manager (well, maybe not now with vim 8 supporting that out of the box :-), and depending on what you're writing, some integration with a tag tools, like cscope, perhaps a search-tool like Ag/The silver searcher: https://github.com/rking/ag.vim#readme

As for plugin manager, I'm personally in the process of moving - I'd suggest looking at Vundle and/or vim-plug.

Finally, you can generally count on any unix-like system to have some form of vi(m) installed -- I'm not sure I really see that as such an important point, but does make it easier to edit stuff on a server with only ssh open to the world. But that stuff you're editing should probably be in a VCS, and use some kind of automated push to land on the server anyway! :-)

[1] http://yanpritzker.com/2011/12/16/learn-to-speak-vim-verbs-n...

"A Tour of the Acme Editor", by Russ Cox [2] https://www.youtube.com/watch?v=dP1xVpMPn8M