System backup and restore with help of Google's system backup feature doesn't seem to work
Unfortunately, it is very temperamental and depends on the device using the Google setup wizard.

It works a bit too well on my s2 with Cyanogen 10 - Cyanogen uses the default Google setup wizard.

When you reset, ensure you follow the setup wizard, and especially notice the part about restore - it should be checked by default, but may not be.