I switched my neovim setup from ale and deoplete to coc.nvim a few months ago, and am thrilled about finally being able to write also all my java with neovim. There are a few rough edges, and of course java features are miles behind IntelliJ, but the benefit of being able to use one editor to rule them all, is a massive productivity boost. Don't think I'll switch back. Also Typescript with a language server is working really well.