Just to weigh in my decision since I have been looking for cover after purchasing the iPhone X, decided to get applecare+ while purchasing just incase I dropped it while opening the box!
I've decided to keep the applecare+ at least for a while. Due to the excess for screen damage being £25 or £79 if the whole phone is damaged not to mention the extended warranty, coverage for accessories that are in the box which aren't cheap as well as the battery being covered for holding under 80% charge over 2 years. Considering apple rates the battery to still be holding 80% after 500 charge cycles doing one full cycle a day means the battery may be worn by this time, which is a £79 repair itself that should be covered with no excess. I'm certain no other policy will cover the battery either since its a consumable part.
At the end of the day you can cancel AppleCare+ within the 2 years and still receive a pro-rata refund as long as it hasn't been used.
In the back of my head I was thinking what's going to happen if I loose the damn thing though. Ended up going with a joint Natwest Silver account with my parter, £6 a month each and £100 excess for loss, theft, damage or breakdown outside of the warranty. However the European travel insurance and tastecard is handy, not to mention you can get 25% cash back on event ticket purchases and 2% back on eligible bills, seemed like after a while its going to bring the cost down on things we would buy anyway!
I know there was a post about where the device would come from earlier, after looking into the insurance terms it seems as if the replacement will come from apple with Natwest. They say the device will be 'like new' and comes with a 12 month warranty from carphone warehouse. Assuming the replacement comes from them, since they are an authorised repair centre from apple they should be getting replacement devices direct. Either way, the terms of the insurance state they will be using genuine manufacturer parts, and any cosmetic parts will be brand new. Sounds like an apple replacement to me!
If anyone has anymore suggestions do post them, if theres something better than Applecare+ I wouldn't mind saving the £199 cost!