I work in I.T. I'm always thinking about backup. I'm a fanatic about it, in fact. At home I backup my PCs to removable hard drives. I have 3 copies. One is always off site in case there's a fire. I'll never lose my photos, videos, etc.
My wife has an iPad and I take the backup of it seriously. So, periodically, I connect her iPad to my laptop and do the sync. It's my job, that's what I do.
Recently I had the occasion to do a restore on her iPad. A complete factory restore. I was a little concerned about doing this as I didn't know the impact it would have. I needn't have worried. The full restore puts the iPad back to exactly the way it was. All of the icons were in the right place. All of the apps were restored properly.
In Yahoo messenger it not only restored the login ID and password, it also restored all of the messages that were sent and received.
The restore was so seamless that nothing was missed or forgotten.
I take my hat off to Apple for making the backup and restore so complete.