Need opinion on which day to do Epcot/AK?

[marriedmarylander]

Do Epcot on:

Arrival day :
probably get to park around 1 or 2PM, stay until closing (9PM) Same day Same day as water park :
get to park around 4PM, stay until 12 midnight(EMH)

Also, are EMH worth it at AK? Morning hours are saturday in May and evening are on Tuesday... Are these worth to take advantage of?

I guess I'm wondering which EMH I should take advantage of and which don't really matter...