My preferences:
Magic over Dream
Terminal: Port Canaveral over Miami. Disney-dedicated / decorated building.
Drive time to port ; Miami over Port Canaveral
5-night over 4-night for experienced cruisers
4-night over 5-night if a chance you get seasickness
Concierge: Dream over Magic. It’s an after-thought on the Magic. Unless Concierge is your thing, it’s a lot of money for little reward on
DCL. Other cruise lines have better Suites than Disney’s somewhat -better-decorated Concierge cabins - at way better prices. You don’t get a different dining room, either. You eat with the masses. You get entertained with the masses. You do water activities with the masses.
I am overwhelmed by the larger ships: Dream/Fantasy, Royal Caribbean Allure of the Seas. They are like floating cities.
The Magic & Wonder have the feeling of being at a resort with free-reign to go where you want (thinking about kids in that respect). The drink and Food stations, ice cream, are close by on the pool deck, where a kid can practice independence and get something for themselves. Things don't seem so far away. Forget something in the cabin? No problem.
If you have go-go-go children who need constant entertainment from outside sources, Dream may offer more or better. I traveled with nieces who never did the clubs. We did more stuff as a family.