When we have managed RD, which was only about 50% of the time we tried, in our two DLR trips, I was never disappointed. No one wants to get up and out the door early on vacation, so the crowds are low once you get inside the park. It was everything people promised.
However, "no one" includes my family, so it was kind of miserable before we actually got into the parks on our second trip, which was in a High Season, August, so RD meant 8am and EMH meant 7am. Our first trip was in a Low, from Halloween through the first two weeks of November, and everything opened an hour later, and that hour made everything
so much easier. We made RD more on that trip, because getting kids up, fed, and dressed at 7am, rather than 6am, is a HUGE difference for our crew. I would blow it off if you have too many Hard to Rise people in your party, because the stress was not what I wanted on my vacation.
That's part of my WDW fears. Because of travel times, our December trip seems to be shaping up like our DLR August trip in that we'll have to get up at 6am (before the sun rises in December Orlando!) to get transport at 7am to make any PPO breakfasts or other 8am events (like possibly changing opening hours as Christmas nears). I changed our ADR+park touring plans so that we won't have to get up early the day after our
MVMCP.
So, go for it when you can, but drop it if you stay out late for fireworks or a party.