I had previously traveled Sea Princess and we had an enjoyable time. However, we had a number of issues with this cruise that we didn't feel were adequately dealt with.
Family Friendly - The biggest issue was the lack of family friendly activities, entertainment and the poor experience with the Kids Club staff. We were advised on the first night, that due to a high number of children on board, there may not always be availability on the kids club. We had to book in advance a number of times. On many occasions, the kids club were not available at all as they had scheduled alternate activities (where parents would need to attend as they were unsupervised). When we did have our children in kids club, we were paged repeatedly for minor things so we had to come collect our children. We weren't able to fully enjoy the other activities as a result.
This wouldn't have been so bad if there were family friendly areas or entertainment for our children. They rarely had any children programming on television, and no other place to take them where they'd have fun. The swimming pool was quite dangerous due to the rockiness of the boat and children were generally unwelcome in the calmer pool.
The cabin was fine - to be expected.