Out of interest, what is it that does justify the cost of upgrading to a moderate if you do have kids? The pools, rooms, something else?
We don't have kids so I wouldn't know. I think most people say the larger rooms, the pools with water slides, and people claim the transportation is better.
We either usually stay at Pop Century, or book a deal with a not-to-be-named travel agency (on this specific site) for a decent discount on a deluxe.