Surely it's the arrival time at destination that matters most to passengers.
Personally never experienced any significant 'late' departure from Manchester that was the result of anyone other than the airline.
In fact, I remember a Captain delaying departure of a Virgin flight from Orlando by 1 hour due to strong winds, and still had to hold at Manchester as the earliest arrival time was 6am (according to the Captain) and that was 1hour 20mins early.