I've found VSCode Vim bindings _really_ buggy. Sometimes non-responsive to the escape key until I press it a few times, sometimes it will kill highlighting of code blocks until I switch modes, sometimes enters `<tab>` in the source code instead of tab when I press the tab button. I still use it, because I've used modal editors for so long and I like everything else about VSCode, but the vim bindings are my biggest point of frustration with it.
Sublime's vintage mode is, in my experience, light years better, if not in completeness, at least in stability.
What platform are you on? I've experienced no major issues with the vscode vim plugin on Mac or Windows.
The escape key issue you mentioned was the only problem I've also had, but it's due to conflicting keybinds between the vim plugin and the vscode bindings for dismissing notifications and context help. I rebound all of those to shift-esc (and I believe the plugin's bindings now do this by default) and the problem went away.
Sublime's vintage mode is, in my experience, light years better, if not in completeness, at least in stability.