I liked them. "The Haunting of Deck Twelve" is a fun episode and one of my favorites; a good Neelix and kid episode. One of my favorite lines is from Mezoti, when she says "Neelix! Continue with the story -- and don't leave anything out!" Pure kid.
Having the kids on board was a good idea in order to explore how the Borg handled this aspect of their lifespans. We got to see specifically how they matured, from the Borg baby on up.
It also continued a view of Seven's life, how it must have been for her after the events of "The Raven." Without the kids, there would have been no episode such as the one with Icheb's parents, which was one of the most emotional and absorbing stories.