We've been on the Ecstasy twice and Paradise once. Ecstasy was our first cruise, our honeymoon cruise and hooked us in. It is now the ideal family vacation for us. Carnival is one of the few lines that changes diapers which is a big +++++++ in my book, even though my kids no longer need them (unless we have another ;0) ) Part of the problem might be that these boards attract many more kid haters than you could ever meet in one place irl and hate ships that are family friendly, which Carnival CERTAINLY is.
We've also been on the Grand Princess and Explorer with the kids, and both have EXCELLENT kids programs too, but I think that Carnival goes out of its way to cater to all kids and I love that they offer group babysitting to all ages so that even the young ones can enjoy the kids room. I heard one mother on the Explorer complaining that her 1 1/2 yo was crying when she dropped off her older child and the little one saw the ball pit. Poor thing kept crying ball ball ball all night according to the mom.
A cruise is what you make of it. If you want a party, you can find it on any cruise. If you want tradition, all lines try to accomodate. I feel sorry for the people who can let such little things ruin their time.
As for the food, of all the ships we've been on, Paradise has had the BEST breakfasts of any, and I believe the food overall on Carnival beats the Grand and Explorer.