Have there been any iPhone without "design defect"? Does any one think "design defect" is not made by accident since Apple fights everyone who tried to fix their iPhone on their own?
The iPhone 5 black paint chipping problem, the iPhone 5 sleep/wake button failure, the iPhone 5 battery problem. The bending issue extends to the regular 6 as well, I've encountered multiple devices in the wild that have it. That's about it though.
I would also argue that all of these issues are more isolated than reports make it seem. No doubt, they are all grounds for a good extended warranty program at the very least but they aren't dangerous, recall-worthy or a case where all devices are affected. Just a significant enough number that if it occurs, it should be a free repair or replacement.
Don't know how I missed that one, maybe because it's not as serious, but I'd say it still counts.
I like my iPhone too, but I am curious what other problems are out there. Seems like they've been pretty solid for the most part, but I say that out of potential cluelessness, not defensiveness.