Welcome back to you and your family, Svein! I'm so happy to hear hear much you enjoyed cruising from a passenger's point of view. Life looks different from the Lido deck!
You're right that NCL, Royal Caribbean and even Princess offer very much the same kind of experience. Vision is considered a mid-size ship these days, as the mega liners go. It's a very manageable size.
What was your son's favorite part of the cruise? Did he participate in any children's activities?