I know a lot of people say that the "really want to eat with the kids", but when you think about how much more time you spend with them all day on a trip like this, not eating with them isn't really that big a deal. Our DS5 only ate with us once, but we certainly did not feel we weren't spening A LOT of time with him. We ate breakfast and lunch together, went to the pool together, did other onboard activities together, went on excursions together, spent time in the stateroom while he ate dinner (from room service or Pluto's) and we got cleaned up, etc.
Trying to sit through a fairly formal meal (yes, the wait staff tries to liven it up for the kids, but it is still a "restaurant meal") for 1.5 hours would NOT be fun with most young children. We considered having him come to each meal, but have his food come first (the one he did attend, the waitstaff did this without our even asking), but finally decided that all of us would have more fun letting him skip the dining room and go to the club.
I hope you work out something that fits for your family. We are going to follow the same scenario this year since it went very well for us last year. DS is thinking of coming to dinner for Pirate Night (same night as Goofy's Giggle Gala) and maybe for the show at Animator's Palatte.
pdarrah