you get to enjoy Epcot,one of the best parks, without hearing "I am bored can we go now"
anyway back to you.
Epcot is fun. lately it has too many thrilled rides for me - Mission:space, Test Track, Soarin' (only a thrill ride if you have problem with heights I do - so it is definitely a thrill ride for me)
go visit the countries in Epcot, if you can work it in be sure to see their activities, plays, bands, etc. Some people think this is the best. I like the rides myself, but everyone has different taste.
if you feel lonely do one of the WDW tours.
I will list them if you ask.
the MK looks completely different from an adult view. Yes it is still magical, but in a different way - hard to describe. but definitely go over there.
notice the little things - Disney is EXCELLENT with all the details.
you have time - don't rush. You don't have to see everything. Go at your pace.