Interesting. What is not clear is what is actually covered. Most iphone issues are DAMAGE and not BREAKAGE. It looks like damage (dropped phone, water,etc) is only covered for 120 days. Breakage in this case must be if the phone no longer works. Way less likely.
Having that extended warranty is good, but the more probably problem is not covered. Or at least how I am reading it.
Manufacturer defects I believe.
Off course if you cause physical damage they wont cover it passed the first 120 days.
But down the road internal things tend to die and devices stop working without physical damage so this coverage will still kick in if you keep it as long as 3 years.
Even if you just need battery replacement its good to have.