We recently returned form a 4 day, and were waitlisted for the main seating. We have a 3.5 YO DS and a 1.5 YO DS, so I REALLY preferred the main seating. Upon check-in at the port, DH was able to get us confirmed for the main seating (the ship was at near capacity, too). The way I looked at it, I preferred DS's to miss the shows than dinner. Next time we go, however, I may consider keeping the later seating. DS's were always napping late, causing us to wake them to get ready for dinner. They ended up going to bed really late, and didn't eat much, anyway. Maybe next time we'll do Pinnochio's or Pluto's, then try eating in the dining room. Also, as many have said before, the late seating will allow you more time w/shore excursions, and less time rushing for dinner.
Woobie