One of the biggest reasons I, and a lot of other Android users, would want to root their smartphones and tablets, and install a custom recovery, is the ability to take nandroid backups. The stock Android recovery console allows you to only either wipe data/factory reset, or to install legitimate, signed ZIP updates for the Android operating system. Custom recoveries offer you so much more, one of which is the ability to back up all the partitions – system, data, cache et al – which lets you restore the device to the state it was originally in.