Ireland's Premier airline? According to whom? Aer Lingus stopped being a 'premier' airline a long time ago.
Anyway, regardless of those facts, I will always try and fly AL unless A: They are too expensive (which is most of the time on Transatlantic Routes - and you can check that with a number of sources) and B :Their service isn't particularly good - like not having individual AVOD. They must remain the only major long haul carrier not to have seat back AVOD in all their aircraft.
I'd be interested to see what would happen their passenger numbers if there was no pre-clearance in Dublin.