Although nowhere near to your situation, I lost important meeting notes after a conference call. After making some formatting modifications (cut/copy/paste) to organize the notes, I found myself not being able to restore any text by undo-ing some of the inadvertent changes I made. Having been burned by a feature so basic to document editing as Undo, my next steps were basically to export all of my business notes and stop using the service for any work related activities. If not for this incident, I would probably keep using it.