We travelled on the Disney Dream May 13-17 with our 3-year-old son and 5-year-old daughter. We had a wonderful time. I read nearly all these reviews before we left, so I won't repeat anything, but will give my brief opinions on what has already been said.
We had no trouble with the elevators, really. Unless a ton of people were leaving the deck party all at once, or a show all at once, there was rarely a wait. We just used the stairs when there were lots of folks leaving the same venue all at once. Never any problem.
Service was great, especially the stateroom service and dinner service. Our dinner servers were incredible, really, and knew exactly when to bring our dishes and our kids' dishes. They completely understood the need to eat fast with young children. Once I had to leave with my son early, and they packed up two desserts for my husband to bring back to us.
The Crew is fantastic. A Crew Member at Castaway Cay showed me the way to the bathroom, while I carried my son. He even grabbed my bag and carried it for me.
The best advice I got on this forum was: (1) wear a watch; (2) get to the princess greeting 20 minutes early (and that goes for Tinkerbell too, I found out); (3) ride the Aquaduck first thing when you get on the ship, and then at night; (4) pools are fantastic at night (~ 7:30 p.m. for us with the kids).
The pools are crowded, it is true. That would be my only criticism of the entire trip. My daughter just wanted to swim, swim, swim. But we knew the pools would be crowded based on comments on this site, and we were prepared.
There is ALWAYS something for everybody to do. My son and daughter have completely different interests, and they both had fantastic time. We loved the cruise. Not necessarily a "relaxing" trip, but completely fun-filled.