On
DCL you don't have to book the entertainment. There are assigned dining room tables with 2 possible times: approximately 5:30 pm or 8:30 pm. So no worries about booking your dinner reservations. Your servers are ready and waiting for you every night and ready to pull your chair out for you, call you by name, and ask you how was your day. There are optional reservations that can be booked but not required. Those would be Palo (adult-only dining room that is extra cost), and also many types of wine, whiskey, and tequila tastings, also small extra cost. On a normal cruise there are port excursions that can be booked through the cruise line which would not be available on a cruise to nowhere.
All of the shows (usually in the Walt Disney Theater) are first come/first served, with seat saving not allowed. Most days there are 2 shows: early diners get a later show and late diners get an early show. They don't actually check which dining time you're scheduled on. I suppose you could see both shows if you really wanted to.
What I like also is that most room service is included with your cruise fare. After it's delivered, someone often calls our cabin to make sure we're happy with our room service. Compared to Disney parks, it's VERY relaxing, but really you can be as busy or as lazy as you choose.