Does it really work wonderfully for you? I am often times shocked by how it just can't guess the most obvious completions. Then I jump into VSCode to sanity check, and it works fine there.

Talking about tpope's official neovim plugin

Just tagging in for comment OP.

Copilot really does work wonderfully for me, as expected with any AI code completion. I run copilot and coc.vim simultaneously, to be noted. So when I just want to autocomplete a word, it'll be coc.vim, but when I want a whole line/method/etc built I'll let copilot be my copilot.

It's not perfect, but it's still generally valuable. I do still bounce between VSCode/NeoVim (depending how often my current task will need a stable debugger vs how often i need better neovim code search), so I see how the VSCode implementation is better; but I still prefer to live in neovim as much as possible.

I gave it a try the other day using copilot.lua, and it made the whole editor unusably slow. It somehow caused syntax highlighting to "lag" for tens of seconds every time I made any sort of edit.

Maybe I need to be using the official plugin, and maybe I need to disable LSP based syntax highlighting, but that makes me wonder what it's doing.

What languages and LSPs are you using? I've never experienced this with Python (pyright), Go (gopls) or Rust (rust-analyzer). I'm using tree-sitter for syntax highlighting. The only special thing is that I'm using lazy.nvim (the plugin manager) to load copilot.lua on the InsertEnter event.

I am using typescript with typescript-language-server. I'll give the lazy stuff a try, but I am not sure why this would make the editor more responsive outside of the initial load.

I have pyright/shell running happily with lsbconfig and haven't noticed any lag. There's a way to profile plugins to see what's killing you I think.