I have never had to have any 'apple' product repaired or replaced, but I am now on my third set of beats in six months. An employee at the apple store told me these headphones in particular tend to fail. What I am glad of is each time they replaced the headphones with new ones along with a new warranty period.
You reminded me of something...
I said in my longer comment that everything not called out as an issue was ok. I forgot about Apple's premium 80$ earbuds... And the lightening cables...
The strain reliever where the plastic earpiece tapers down to the cables, and the similar cylindrical strain reliever at the plug end are made of a really crap polymer that is sensitive to body oil. The same could be said for the flexible portions of the iPhone 4s bumper surround and the lightening cables.
These polymers eventually reacted to my body oils (I use no lotions, creams or perfumes) and swelled, split, became gummy and/or embrittled and crumbled away.
After a irritating and disappointing argument with an apple representative about this issue (note: I didn't often use the earbuds because I use a Logitech rechargeable Bluetooth headset, and only used the ear buds a few times when the battery got empty on the headset), I considered myself lucky to get a replacement set.
I had such bad experiences (mostly having to argue to convince the person of how much worse the premium set was compared to the free set) with these polymer issues and their short longevity that I was really afraid to buy an Apple Watch for fear of seal integrity longevity around the Digital Crown, on/off button, speaker/mic membranes, as well as between the metal housing and the display or sensor array (so far no issues after 1 year though.)
Note:
I must note that I feel rather guilty for airing these issues because in more cases than not, Apple has been really good.
I'm not a disgruntled customer, But I think it ismportant to discuss these things and not pretend there can't be an issue. My speaking out here is due to the bad experiences with a few Apple reps that were not as customer focused as the vast majority of their colleagues (and were some combination of condescending, seemingly making up a narrative to try and persuade me to accept a situation and go away, or seemingly disinterested in getting feedback on issues causing significant dissatisfaction and loss of confidence.)