My wife has my old 5s on IOS 9.1. She is on the device a lot, because it's her work device and primary social media device. Has her ipad 2 on 9.1 and a new SP4 as well. She has no issues and the only time she seems to need help is when I change router settings and disrupt the wifi. When I gave her the iphone, it was:I can sympathize with all of these (I'll stick with the Mac for a while, though, because Windows is still trash). There are people who are made for the iOS environment. My wife is an example. However, as of late, there have been countless issues with her devices. I spend an hour fixing her contacts, another half hour figuring out her calendar accounts. It's just the same troubleshooting and "wizarding" that Jobs and Forstall hated.
...
1. backup old device
2. restore new device
3. hand it over.
Of course the above did take some time, but I didn't have to babysit anything.
Could be happier with "just works", because I'm busy enough and don't want to troubleshoot IOS issues. Everybody's mileage is different across the range of devices.