I've never had any of the issues in the post. I know iCloud sucks for developers (seems like iOS 8 is rectifying that a bit) but for me as a user it's been very reliable. Am I just lucky? Is the experience detailed in this post very common?
P.S. You don't have to use iCloud for anything. iOS supports Google Calendar/Mail, Dropbox has an API for file storage dev can use and with the new document extensions it's easier than ever to use. You choose to use iCloud of the devs of your favourite apps choose to use it.