We've cruised
DCL twice, and HAL's Zuiderdam in the Western Caribbean this summer.
There were a fair number of kids on HAL, but nowhere near as many as on DCL. The ones we spoke with were enjoying the kids' program, but we had no first hand experience with it (DS chose to spend time with Grandma instead of cruising.)
We had a beautiful little suite and concierge service- and the price was less (a lot less) than a category 6 would have been on Disney.
Food- wonderful. Entertainment- I thought it was on par with Disney, although not aimed so much toward the kids.
Wait Staff- mostly Filipino. Very polite and courteous, but not as playful as on DCL.
There was a more relaxed ambience on HAL, more nightlife, a gorgeous dining room, a terrific alternate restaurant (on a scale with PALO- impeccable service and exemplary food.)
All for a lot less $$.
I do want to comment on HAL's "no tipping" policy mentioned by another poster: HAL's policy actually "no tipping REQUIRED". They do not add the tips to your account, and they do not publish any recommend tip rates. This does not mean that you should not tip- only that the tip is between you and your servers. PLEASE, for the sake of all those you serve you during your cruise, tip your servers appropriately!
I would not hesitate to cruise HAL again- at least on one of these newer ships.