I use Neovim on daily basis. It works really well. It requires tremendous efforts and love to transform a huge archaic code base into a much modern one. Thanks, Neovim team!
This can be said for any rewrite. Let's wait and see what happens to Neovim's code in coming 10-15 years if it can last that long. When you have to support all the legacy systems and all types of OSes out there, crap is going to come in the code.