These days, buying a new phone is pretty much the equivalent of buying a new laptop - or wiping and reinstalling the OS on your existing machine.
This is not always the case and Apple are very good here. When I lost my 6 and had a replacement, after restoration it felt like I was on the old one again, and the daughters upgrade when switched on simply found old one alongside it and asked "to you want to transfer ?" a short while later she was up and away.