did the route via Dublin couple of years ago and was very impressed outbound by the efficiency and speed of pre-clearance compared to some of the huge arrival waits stateside (over 3 hours last year in Orlando) . However, return NY to Dublin is a very short overnight flight and by the time there had been a couple of rounds of drinks, meal service, duty free, scratch cards and god knows what else there was stuff all time with the cabin quiet and lights dim for sleep. It is the ultimate red-eye as when you arrive knackered there can then be a fair bit of waiting in Dublin for the onward flight to your UK destination.