This was my experience as well. I don't know how anyone is able to use it; it brought my 2017 MacBook pro to its knees every time I would start writing a HN comment. I uninstalled it after about 5 minutes.

No issues with speed or anything, chromium, linux.

I had no speed issues here, either. Chrome, Windows and OSX.

That said, I removed it because the button in the lower right kept getting in the way of things like resizing the textarea.