I like the late seating for dining for several reasons:
(1) I usually eat late anyways.
(2) With late seating you don't have to rush getting ready for dinner. Early seating starts at 5:30 (depending on your rotation) so that means starting to get ready at 4:00ish so that everyone in your cabin can have a turn in the shower - at least in my family. With late seating, you can relax in the late afternoon instead of rushing to get showers and dressed for the evening. Usually I take my shower, put on casual clothes, see the show and then go back to the cabin to put on my makeup and do my hair after the show before dinner.
(3) I also like to have a relaxing cocktail before dinner and with early seating that would take place really early - like before 5:00.
(4) If I had early seating and was to go to the later shows after I had eaten a large meal with wine I would be asleep in no time flat.
(5) And the late seating seems to be a more relaxed meal because the servers don't have to "rush" you out for the next seating. (Now that can be a problem sometimes because your meal can drag on - especially if you don't like your tablemates.)
I can certainly see the appeal of the early seating if you have smaller children or you are an early to bed kind of person. But for me the late seating works better.