We did EMM at both MK and DHS last week and I was really surprised that it was wonderful! We rode Toy Story multiple times without getting off, and my niece was overjoyed that we were able to ride Star Tours by ourselves.
We rode Toy Story Mania and Star Tours as many times as possible prior to 9am, then we headed to breakfast. I was pleasantly surprised that breakfast was done really well. It was better than any other breakfast buffet I've been to in Disney. We were given a warm welcome, the food was hot and always neatly presented, and there was a good variety. We absolutely loved it. It felt like only 3-5 other families were eating with us. When we left breakfast, Minnie Mouse still only had a 5-10 minute wait. Toy Story broke down while we were eating, and we were told that we could use the fast pass line all day (we didn't do it though). In fact, we left DHS by 10:30 and headed to Epcot. On our MK day, Peter Pan wasn't operating until 9am. They opened the tea cups and carousel to make up for it, and we were able to ride PP until 12pm (although the FP+ line was so long we chose to only ride once).
My family would definitely take advantage of EMM again, and we're hoping that they'll do it for Epcot eventually. The quality of breakfast and being able to ride certain rides with no waits made my family feel that it was worth it. However, the hour goes by WAY TOO FAST!