i'm using an iphone 3g, i posted a while back looking for a fix, the headphone jack/vibrate switch are finished. no sound to the right 'phone, and if you wiggle the very loose jack, it will switch the vibrate on/off (so you walk, and the thing continually vibrates). just pressing on the case sets it off. the silver ring around the jack has completely failed and fallen off in several small pieces, cracking the case around it. and the plastic case back has a split in it, something i saw on a friend's iphone as well. the metal piece that pushes on the two volume control buttons also fell off, never to be seen again, so i have to keep a fingernail to adjust the volume by that switch. the screen became very scratched and many, many pixels are dead. i would estimate in excess of 50, five-zero. you can see splotches and strings of pixellated gray that do not go away, even with knox's stuck pixel app, which doesnt fix the live-but-stuck pixels. to top everything off it freezes/crashes more often than not and takes a while to reset. not good when it bugs out on an important call, locks up, and you have to wait to reset before you cal call back.
but, i've had it for almost 3 years now with very heavy and abusive use, so one could say its at the end of its service life. until the pixels and the trouble with the headphone jack & associates it has been a very good phone, survived many falls higher than 2-3 feet, and even an accidental toss by a stupid buddy... right the day that i got it. i really think you will have to replace that ribbon cable (google and you'll see it is a very common problem) but if you treat it like a PDA and not a cell phone, i think you'll be happy with it. durability wise it has taken a beating, but shown it as well. i guess it depends on how you treat it, it will survive mistreatment but not like your average joe phone would.