I've always heard the clean install is best, but I am not prepared to wipe all my text messages, Notes, voice memos, etc. There just doesn't seem to be any manual way to save all these things. In fact, even though I got the 5S a year ago, because I did it as a new phone, I've wound up keeping my old 4S just so that I can still have all my texts (4 years of texts) and data etc. Apple just seems to assume that we don't want to keep that stuff.