I don't think the size of the room and the placement on the ship makes the comparison apples to apples. Just today someone asked me when we sail with Disney is it the same "magic" that the parks have. . . I said YES. Absolutely. For me at least. There is just a "feel" that isn't there with other cruise lines, in the same way that there is a feel in Disney parks that isn't there in other theme parks (which are also fun, but just different). On
DCL, aside from the Disney touches everywhere, I love that there is no casino and that the main focus on a DCL cruise is kids/family. That is the differentiating factor for me. The entertainment is mainly family oriented, the games and activities incorporate kids and parents all the time - like the game shows with the parent and child playing together. Generally speaking, the Crew go out of their way to recognize the kids at every opportunity. They just make kids feel so special.
I may be totally off on this because I have not cruised with kids on other lines and wasn't watching out for kid stuff. Maybe if I had cruised with kids I would more easily see some of the "kid" friendly stuff on other lines, but objectively speaking, I never felt on other lines that kids were the focus at all. You can't escape that "feel" on DCL.
If we were just looking for a cruise or a vacation or a certain type of room or itinerary, then money maybe would be the most determinative factor and the comparisons would be more apples to apples. But when we do a cruise with DCL, we do it for the whole experience - not just for a cruise. Just my two cents.