I made the fatal mistake of setting up as a new phone when I got my 6S+. I spent literally two evenings transferring photos & videos over, and then creating a new backup. Well this evening due to one or too small iOS9 bugs, I decided to erase all content and reinstall my fresh backup. I had an iCloud backup and I didn't need my phone for a few hours, so I had absolutely nothing to lose... Hmm. The backup loaded without hitch but hey, where are all the hundreds of photos in my Photo Manager Pro app? Where are the videos? Why is my camera roll all jumbled up? Why have none of my apps saved their passwords etc? All apps were toggled in iCloud, and my last backup (successful) was 14GB. However, only around 2GB has actually loaded onto my device. What an absolute crock. Fuming. Of course I'll try it again but I'm not holding out much hope because iCloud has been a PITA ever since iOS9 for me. No auto-backups have been managed and I've had several 'the backup could not be completed' efforts. iCloud used to be a Rolls Royce service.