I have always booked myself dining res. based on attending the parks with EMH. This trip we did the opposite. If a park had them, we went elsewhere.
It worked great for us. We were there over march break 7-15, expected some crowds. We didn't wait any longer than 10 mins for a ride (we don't do the thrill rides yet- small kids). We used FP when the wait was longer than 20 mins and we ate during the mid afternoon and either went back to the room or stayed to watch the crowds or rode the trains/monorails.
We did do one EMH at epcot on the last night. It was worth the crowds, but we held off getting there until after 6pm and were able to ride Soarin 2 times in a row with only a 30 min wait (the only long wait of the trip). We really like to be at the parks during the dark- it's a whole different feeling. So you have to watch for the closing times if you are going to do this at MK.
So if some of your reservations are at a park not having EMH, consider this a test. See if you find the crowds better. I felt that we didn't give up any of the "value" of these extra hours by not attending these parks. We got to do all the rides we wanted, didn't have to wait as long and generally had a great day at less crowed parks. Getting back to the resort earlier also meant less cranky kids, mom and dad!
It also allowed for easier planning, I had at 2 parks to choose from (if I avoided the park with early hours and the one with late), and really I feel the late ones are the priority. I took a look at the weather for the week and tried to go to the waterparks, AK and MK during the nice days. If rain was predicted, EP is a great choice, or a visit to DTD and Disney Quest.
Good luck