I'm with TSR2 on this point......
EI are trying to ensure their are the main airline on Ireland-USA routes. How can they ensure they achieve this position if they are operating B757's with 1/3 less crew which then means a lower service level onboard. Whats the config? 12/170? I know another airline which has 189 and 4 crew......
5 crew ensure situations onboard can be handled without stopping service. (Anytime I have seen an ill pax onboard an aircraft it usually takes 2 crew to deal with the issue)
If I was a UA/DL/US passenger the offering from EI would not really interest me.