Aer Lingus can be pretty bad at opening award inventory on flights between Ireland and main land Europe. I once used my AA miles (when EI were in OW) to fly SAN-LAX-DUB[1 month in Ireland]-FCO-DUB-LAX-SAN in J. Problem was I had to fly to Madrid with Iberia to for the Rome legs. Although EI had a daily flight, it had no availability.

If you are doing DUB-CDG do consider Cityjet/Airfrance as bag is free (unlike EI).

I believe I once flew Boston to Shannon in 4hours 45min. Now that is short.