We sailed the Zaandam out of Canaveral about a year or so ago. We are experienced cruisers ( 22) and had no complaints. The food, waitstaff, cabin steward and everyone we had contact with was fine. Sounds like you have cruised some so you know there are those who complain because they think it's expected of them.
The embarkation / disembarkation shouldn't be a problem for you.
Canaveral is an easy port to go through.
Can't compare to Raddison as have never been on same but there won't be kids galore as on Disney and I think you will be pleased to find you have stepped up a couple of steps from Royal Carb.
Take a deep breath, relax, go with the flow and all will be well.
Hmmm, how do you ever do anything if you won't do anything for the first time??? Seriously, the Zaandam is a wonderful ship and you will enjoy it completely. Be sure to check out the Crow's Nest, it is the best place on the ship.
Favorite line is a matter of choice, but having sailed both Celebrity and HAL, I think HAL is much better. I found the service and the food on my HAL cruises to be way ahead of Celebrity. Heck, I thought service and food on Carnival was better than my Celebrity cruises.
Noticed you sailed Disney - are you sailing on the Zaandam with any children? Thinking of booking her next Feb and will be traveling with my 8 and 6 yr old. They loved the Maasdam last yr and we are booked on the Zuiderdam this August that has extensive Club Hal facilities - so going back to ship with "makeshift" Club Hal facilities may be a disappointment for my two?
Really don't see the merit of checking out a cruise before taking the kids - your attitude and the people you meet play the biggest part of cruise enjoyment in our book.
It's to be expected that kids love Disney - HAL does not specialize in kids although it does have kids and teens programmes - during school breaks they are in high gear - not necessarily so during other times of the year.