Your issues really sound like they're hardware-related. It's not surprisingly that hardware problems would occur in a few instances, given that Apple is pumping

Your issues really sound like they're hardware-related. It's not surprisingly that hardware problems would occur in a few instances, given that Apple is pumping out millions of these. Fortunately, Apple is pretty good at replacing defective specimens. Counter-anecdotally, I've owned a sequence iPhones starting with the 3G, and I've never experienced any serious glitches, ever. I remember Safari used to crash a few times a week on iOS 8, but that's ages ago.