We've not long got back from 2 weeks at Disney in Florida. We have a 9 yo and a 4yo.
We had a blast - the absolute time of our lives. Really. It was as good as that. The DCs had smiles on their faces the entire time, often trembling with excitement. They literally danced in the streets.
The shows were unbelieveably good. The same with the parades. The fireworks are breathtaking. The place was just so joyous.
DH and DD1 are very into rollercoasters, so were obviously in their element. DD2 and I are into more gentle rides - there are so many of these, and all done so so well.
There were also so many rides we enjoyed as a family.
We've been to Disneyland Paris a few times and had an amazing time. Florida is better in its sheer scale.
For Paris, the best age is 3 plus I think. For Florida, the flight is long but our 4 yo enjoyed the flight, and it was really worth it for the time we had.
Everyone likes different things of course. But Walt Disney wanted to create a place for the whole family, grown ups and children, to have fun together. I think they have created that place for our family.