When we took our first trip with our son, everyone recommended the midday break. It went awful!!! It took 15 min to get back to the front of the park, then travel time to the resort (30+ min), then the walk back to the room (10+ min). Half the time my son fell asleep during the process or wouldn't sleep at all, totally defeating the purpose. Then we had to repeat the whole process in reverse!
Not only did it waste a ton of park time, but it added a lot of unnecessary walking that left us feeling more tired after our break. Now we rest in the parks and just stay as long as we can. Some days we rope drop and stay until afternoon and some days we arrive late and stay through fireworks. My son naps in the stroller. And we are so much happier!!!
If you do plan for a midday break, I would plan on at least 5 hours. You will easily lose at least 2 hours in transit and I would want at least 3 rest hours to make it feel worthwhile.