That has not been my experience with vim (over the past ~12 years). I don't run a huge amount of plugins, but I do use a few. The only thing I have a noticeable occasional lag with is the parinfer clojure plugin (in neovim, and its more that the plugin lags before applying its changes rather than vim itself lagging - the author does acknowledge that its currently sub-optimal). Syntax highlighting has never caused any issues for me. I wonder why you are having issues... that does sound rather annoying.

I was also referring to the typing latency as measured by the benchmarks here: https://pavelfatin.com/typing-with-pleasure/ As you can see, vim's text input latency is measurably lower than most of the other tested editors on most platforms (zero-latency IDEA seems to beat it in some cases).

That’s a broken highlight syntax file. The good ones don’t highlight text until it becomes visible in the buffer. You should bug it if it is reproducible in neovim. The team is highly responsive.

It happens with large javascript files (bundles). I use this:

https://github.com/othree/yajs.vim

And my color scheme is:

https://github.com/nanotech/jellybeans.vim

Not sure which is at fault (if either).

Yeah, yajs hurts performance. There's actually a disclaimer on that landing page you sent me.

Neovim has its own js/json highlighting out of the box and it's pretty crazy fast for me.