MK- the EMH will be better utilized IMO. I think you will get on more in demand/long line rides at MK than at AK. If you don't have any FP at AK/Pandora, then I say head to MK. From what I've read, it is still really busy for EMH in the AM at AK. We were there mid August and had no luck with the morning EMH to get on FOP unless you arrive before 7am and wait for rope drop. We got there right at 8am and it was a 3 hour wait. So we did NRJ and visited the other lands and left. In retrospect, I wished we would have just gone straight to epcot since we hopped that day. We had better luck during the evening EMH at AK and we got on FOP in less than one hour at night. Plus to me, there is nothing like being at MK in the morning when it's empty, it's always been my favorite. We do MK EMH in the morning when we can, we usually can do Peter Pan a few times and mine train.