I've always been curious why there are so many +Android backup applications. Technically the backups are trivial - apks are at a known place and each app's data is at a known place, so just grab that stuff for backups and put back for restores. Android 4 has adb backup/restore commands which do pretty much that. Simple, effective, what could go wrong? Short answer: it is quicker to just delete your data. Those backup apps exist for a reason.
Yesterday I decided to wipe my phone and tablet back to factory images. In particular I wanted to encrypt them, and I did want root, but didn't need +ClockworkMod recoveries which rooting usually require you install first. +Chainfire has a CF-AutoRoot that does that for you.
Backing up the phone gave me a ~400MB archive (I didn't include apks since they can be easily redownloaded). I did the wipe/factory/root/encrypt dance and then did my restore. It had no effect as far as I can tell. And I had to manually select every app I wanted again in the Play Store. Doing another restore after that still had no effect.
Having learned my lesson, I did a backup of the tablet including all apks. It was ~12GB. Did the wipe/factory/root/encrypt dance and then did the restore. It restores one apk and then the Android gui crashes, restarting itself a few seconds later. This is completely repeatable. Gui crashes don't have a crash reporter so Google won't even know this happening. And I'd love to hear the explanation as to why a restore would crash the whole gui environment.
I could of course manually dig things out of the backups, but that would be far too time consuming. There is no unique data on the devices so I didn't actually lose anything. But the reinstall of every app, having to supply usernames and passwords to so many of them, changing settings, and placing them in the right places in the launcher is really tedious.