Hello
I have purchased DIsney insurance and used insuremytrip dot com as well. The most important factor in the insurance is the exclusions IMHO. Any pre-existant condition is excluded Unless you purchase a policy that covers it or adds it. Disney does NOT cover ...Many do not realize that IF per say someone got ill while on trip and then got ill during the trip it would not be covered....it is the Look Back Date (how far they look back) so another example is...If say your FIL had a heart condition, then heaven forbid had an issue and you had to cancel, no, that too would not be covered unless it was added/waiver.
IF you are looking for just basic coverage, you can go Disney, IF you are looking for better/more specific coverage, the other carrier is very good, well respected and I have used them for cruising..issues and once for a claim that was in the thousands. The ins. covers what you pay OOp for, so if you get credit back for a part, that is also excluded.
Just want to mention that adding disney ins can be done until you make final payment but cannot be refunded...so many don't add it on up front. Using the outside source allows you to get various prices, various options AND you can literally purchase it on the day of departure (though not sure why someone would wait that long)...longer you wait costs a bit more...
Hope this helped a bit....many skip ins...But if you have any doubt about losing $$ for sickness or canceling it is worth it IMHO...been there and had to use it....Good Luck deciding!
Oh, just want to also mention that looking at that other site will explain insurance as well...take a peek may help you decide.
Have a great, safe, healthy trip!