But then I finally read some blog posts and documentation and it clicked. I'm not looking back, either.
Even though I'm Emacs-inclined (though not living in Emacs), orgmode is too unwieldy and complicated for me, and the "killer missing feature" is quick entry and editing on my mobile phone. OneNote does that very, very well.
I do live in Emacs, but I prefer the mouse to the keyboard for tasks that can be done both ways, and balked at learning the many dozens of keyboard shortcuts ("keys", in Emacs terminology) org mode wanted me to learn.