It is not backing up all application data. Instead of taking an image, it seems to only be backing up a limited amount. If my iPad is currently consuming 14GB of data I should be restoring a full 14GB. Instead, when I restore it will only do about 8Gb, and miss important application data. Previously, Itunes would backup the current system state and then you could restore it fully to another device. That does not seem to be the case anymore.