Our family (a three year old, two parents and four grandparents) all generally enjoyed this cruise.
The ship is a very manageable size, which makes it very convenient for travelers. As others have noted, there are some maintenance issues with the Ryndam and hopefully these issues will be resolved during its dry dock in March. Travelers should bring layers in case the room is very cold, and be prepared for the possibility that the ac may not work in all cabins. My mother's cabin was very cold, and the problem was initially helped with duct tape, and fixed the next day. HAL kindly sent her a bottle of wine for the inconvenience.
Please utilize caution when turning on the water in the faucet or the shower, as the water can be quite hot if set to the maximum temperature. As long as the faucet is set to the middle temperature, you will be perfectly fine.
This is a connecting cabin, so people who are very sensitive to noise may wish to choose a different cabin. The people in the next room were very quiet, so we did not experience any difficulties. But with louder neighbors, you really might experience a lot of noise, as there is very little soundproofing between the connecting cabins. I did not realize this was a connecting cabin prior to booking it, and would not have done so since we were traveling with a 3 year old who might have disturbed our neighbors. Thankfully, he slept quietly through the night but he did wake up quite early in the morning. Most of the cabins on deck 9 face interior crew space, and it is hard to know how loud or quiet that space will be in advance. We did not hear any interior noise in our room. There was some limited noise from the Lido deck announcements, but it wasn't too loud or distracting. This cabin is also located close to the laundry machines (there was no noise from the laundry) and fairly close to the elevators.