I can't speak to the strengths of the VScode plugin, but if it's anything like the emacs gdscript plugin (which I use with Spacemacs + vi keybindings), then the integration is very tight. I get just as much completion as I do in the in-engine editor, I can run/debug/breakpoint etc. I've been using it for ~2 years.
I find the Godot native editor annoying (and it lacks vi keys!) amd clunky and long for multiple tabs but it increases productivity enough that I wouldn't give it up.