We have little ones so we stick to their daily routines on vacation so they eat at the same time they normally do. This makes it easy for us. The only thing that varies on vacation for us is bedtime, which tends to be a little later than at home, but they also sleep later on vacation or nap more. However, they tend to be hungry at the same usual times! A no-brainer for us and we are also hungry at those times since we are used to eating on regular schedules. For others who are more spontaneous it could be a pain, I understand. For us, it works out well. In fact I would feel like more of a slave to the restaurant if we were unable to make ADRs and had to guess how long the wait will be. Seems much more stressful to me!