The only time I've ever seen real-time Google Docs collaboration has been during meetings which should have been an email. Total waste of everyone's time. Not to mention the horrible UX of people constantly moving their cursor around and moving text around. I'd suggest that pass-the-baton style collaboration would be a much better UX if you absolutely must collaborate real-time on creating a document. Which I find the premise to be incredibly dubious to begin with.
Even if actual realtime collaboration is rare, there are other collaboration features that are missing in most desktop equivalents, like getting notified of changes, being able to mention people in comments, etc. that I do see used quite a bit.
But my experience is that realtime collaboration is useful. In particular, immediately after emailing a doc to multiple people it is not at all unusual for more than one person to be actively looking at commenting on, and maybe changing the document at the same time.
