Hi,
I decided to go with Ryanair this time. Its only for a 2 day stay in Rome for a wedding, and I have seen the Eternal City before. For two people Ryanair worked out at €440, including bus return to city, while Aer Lingus was coming to €587, including train return to city. The price differences were too much for me to ignore, and I wanted to book flights now. Maybe flights might be cheaper in 2 months time, but they may be dearer too. I went for the priority boarding too, but only because I am tall and my wife is tall as well, and we like to get the emergency aisle seats for a bit of extra legroom, especially on flights of 2-3 hrs.
Last year we went to Seville with Ryanair, ( Aer Lingus didnt fly there from Dublin). Fair play to Ryanair, only direct flights from Dublin. Everything was grand, except no priority boarding in operation on return journey, but we got emergency aisle seats anyway. On contacting their Customer Service, we got a refund of the priority boarding fee for the return leg.