We went last year (me, DH, DS10, and DD 7 at the time) and found it interesting and moving. DH has always been interested in the Titanic, so he was really looking forward to our visit. He is also planning to take his mom to see it on our next trip.
One comment, it can be sad, maybe difficult for sensitive children (and adults, for that matter) at the end when you check the list against your ticket to see if you were a survivor. I was the only survivor out of our family...interestingly, I felt especially sad as I thought how I might feel had I lost my family members and fellow passengers on the Titanic. You may want to prepare your kids and/or plan to be sensitive to the feelings this exhibit may invoke.