(neo)vim enables extreme productivity in ember (if you know how to use it) — but that could be said of any of the other editors as well.
This guide gets you set up from nothing to fully operational.
You'll want to remove any linter / completion manager you currently have installed (or disable them for js/ts/hbs files), and follow the install guides for the following packages:
coc takes control over all linting, hinting, and language-server integration
Ember plugin for coc, uses the Ember Language Server
Optional addons for Unstable Ember Language Server
Syntax for Ember Templates
Install the latest nightly build of neovim: https://github.com/neovim/neovim/releases/tag/nightly