We had an absolutely amazing time. The service was outstanding - I kept having to tell the waiter not to cut up my children's food. The kids kept begging to go back to the kids club because they were having so much fun. They mostly went to the oceaneer club (awesome slide/treehouse play area) but went to the oceaneer lab if there were any particular events they wanted to do there.
My daughter (age 3) loved seeing the princesses - make sure to sign up early at guest services for the princess tea (free) if you want to go - tickets run out fast but some people got in on standby as well for no-shows. Several times we were walking around the ship and we would turn a corner and randomly run into a character. If you are on the ship on a port day, take advantage of the mostly empty ship to see characters if they are available - there was virtually no lines to see the princesses on the day we were in Victoria - the princesses were wandering around trying to find kids to talk to. They had a great show at the end where the kids got up on stage and sang and danced with mickey and minnie for the parents.
The weather wasn't great so we only used the pools on the first day in port in LA. I get motion sick easily but only got sick once on the one really rough day at sea. After the first day we didn't really notice the motion of the boat.
We got first seating (watch out if you are booking online - it automatically puts you in the second seating so you have to change it if you want the first), which was nice since it was closer to the kids' normal dinner time, but irrelevant for bedtimes since the show is afterwards (vice versa for second seating). We never had any real problems getting seats for the shows (which were fantastic and the kids loved them - they put the shows live on the stateroom TVs if you can't make it to one, but it really doesn't compare to going). We didn't usually arrive until right before showtime but there were always seats left near the front left - an angled view, but it was close up for the kids to see and we were close enough to have the glitter/streamers/bubbles/snow fall on us.
If you have mobility issues, make sure to go through Cadillac lounge to get to the show - my mom sprained her replaced knee right before the trip and was in a wheelchair then used a cane but we didn't know about the secret entry until the last show (you can't use it with a wheelchair but if you can walk down a short hallway then they will take you though the door near the stage).
We didn't do much for excursions. My husband and son rode the cable cars in San Fransisco, we skipped Victoria and we met up with friends to go to the Vancouver Aquarium (not an advertised excursion so few people knew about it but it is only a 10 minute cab ride from port).
We had a great time - we did a week in Disneyland first and actually enjoyed the cruise even more than Disneyland. We can't wait to go again!