We had the late seating on the EB Repo.
Initially we didn't think it would be a big deal, and it really wasn't too bad.
The kids have their dinner around 530-6 in the club/lab, but they didn't like it because they would usually go to topsiders buffet and the counselors would bring them food. Understandable, turning 50 5-8 year olds loose on the buffet would be disasterous.
Our show was the early one, at 615. We would pull the kids for the show and go to it, then get dressed to go to dinner at 815. If the kids (we have a 6 y/o and 8 y/o) wanted to have the nice dinner with us we would get them a snack at 530. If the parents are having 'special' drinks at the show, then you can hit deck 9 and get them free special drinks too - our favorite was a coke float. If they wanted to skip dinner and go back to camp after the show then we would give them a full dinner on deck 9 (burgers/hot dogs/etc) before the show.
The biggest problem we had with the late dinner was this - you weren't hungry for the deck parties! You get out of dinner at 930 or so and many deck parties had food and started right away. The early seaters were hungry and hit the party buffet line hard.
So, the next cruise we will try the early seating.