A serious bug in iOS 8's 'Reset All Settings' function appears to be erasing documents stored in iCloud Drive, according to several reports.
A poster on the MacRumors forums discovered the bug after trying 'Reset All Settings' to improve iOS 8 performance on an iPad 3.
Because iOS 8 was so sluggish on my iPad 3 I reset all settings (No data or media will be deleted) and sped it up BUT deleted my iWork data! Then promptly synced and deleted it in iCloud.I have public beta of Yosemite so can't roll back via time machine. I have no pre iOS 8 backups in iTunes or iCloud to revert to (well iCloud device backups don't contain cloud documents and I should have iOS 7 backups in iTunes but can't find any. iCloud has no trash like dropbox. They seem gone forever.