In Word (especially when save-in-place disabled), old file disappears only when the new file is complete. And since file writing naturally walks over all the st

In Word (especially when save-in-place disabled), old file disappears only when the new file is complete. And since file writing naturally walks over all the structures, any exceptions usually happen during save and display time. If the file ended up on disk, it is usually OK. And even if you are unlucky, you can still restore it from your backup (time machine, dropbox folder, restore point, etc..) If you have explicit "save" action, all of those things happen automatically -- there is no need for programmer to do any sort of action here, other than to make sure saves are atomic. Only persistent environments have this problem, because once your persistent-word crashes, you cannot do anything to roll back the change -- other than revert entire OS to previous snapshot, but this will roll back all other apps, too. (Practically, I've had MS Word crash on me hundreds of times. I've only got corrupted save file once or twice. So at least from my anecdotal evidence switching to "persistent world" would make data loss much more frequent.)