How do I backup my N4 and transport it to the N5 when I get it this week? I have heard of Helium, and ADB Backup. But wanted to find out which is an easy and reliable way to do this.
Gmail data and Apps will automatically restore if you selected it in the Nexus 4 settings (Settings-->Backup & Reset). some third party app data will be lost.
IMO - be careful of using a backup app on device X and restoring onto device Y. you may restore incompatible system files. best to do a fresh install and fresh sync from the get go.