Not terribly impressed. I have been working on a 148MiB HTML file the last couple of days, and opening it with textadept was quick enough but it basically hangs when scrolling around.
Notepad++ handles it without any major problems. VS Code almost does, sometimes it has crashed on closing a tab with the file open. Emacs I should not even try... (Wow: spacemacs asked me to "open literally" and the performance is really good! Nice!)