Confession time: I have never updated the OS on my iPhone 5S, which I bought new in November of 2013. I'm still running 7.1.2, which is what the phone came with. The phone was working fine until recently. Lately, though, Facebook has been quitting unexpectedly, and Spotify is having issues with accessing downloaded music when offline. I'm also running into problems with updating apps or getting new ones that require a newer OS. So I've decided the time has come to update my OS. I checked Software Update in Settings, and it says I can get 9.3.3. But in another thread someone said I should consider using ipsw file to update instead. What do you think? Should I just go ahead and update straight to 9.3.3? Or should I educate myself about ipsw and go that route?