So many people on here saying you must be mad not to get AC... well do the maths. Assume you'd bought AC every year you've owned an iPhone - based on the number of times you've used it, has it saved you money over all those years? If it has, then AC is for you, you're probably damaging your phone more than the average person. But if not, why do you think that's suddenly going to change? You've got to take into account the cost of all those years you have AC but don't drop your phone - at the end of the day Apple (and all insurers) have done their homework here - it's quite simply gambling, sometimes you win, sometimes you lose, but the house always wins at the end of the day.
I've had iPhones for 9 years and have never had any insurance, nor (luckily) have I needed it. If I drop my X then that's £500 I'll need to pay (and I'll be very, very pi**ed off), but that's still less than AC would have cost me over those 9 years. Of course, if you're accident prone, wouldn't be able to stump up £500 in one go, or just want the peace of mind, then that's your call. But big money tends to panic people into not thinking rationally.