it really depends on the time of year you're going, but overall, i would make an ADR for dinner because the restaurants tend to be very busy at dinner time and have long waits so having an ADR couldn't hurt at all. it's better to have one and then cancel if you need to, rather then not have one at all and wait for an hour or more to be seated. if you want a quick but good bite to eat (sandwiches), you could go to Earl of Sandwich and eat there and when we went last year (in September), the line wasn't too long and we got our food fairly fast.. if you want something more then that though, make an ADR.