We had late dining 2 cruises ago and initially didn't like it. We were on the waitlist but didn't have high expectations as a party of 10 getting off of it. After going back to main dining on our last cruise, now we're sure we'll probably choose late dining again, even with 3 children (currently 10, 6, and 9 months) in our party. We just felt like late dining gave us enough time to go see the shows where there's only one showing, like the Christmas tree lighting on the Merrytime cruise or the Mickey's pirate deck show whereas this time in early dining, we were always either cutting it close or rushing dinner to get out in time.
Another factor for us is that the 10 and 6-year-old would snack during the day anyway and wouldn't be ready to eat by the early dining time anyway. This past cruise we would get them snacks at 3-4pm and then they wouldn't be hungry until after the shows.
So the next cruise we'll probably switch back to late dining to try it out again.