Main concern was reliability and making sure that I understand ahead of time requirements if we fly Ryanair. From reading the other threads, sounded like they are apt to cancel and flight and leave you hanging?
Looks like main requirements that must be followed are On line check in and proper baggage requirements.

They would be flying out of Dublin on August 21 on points so did not want to miss that flight. Im thinking best option might be to fly back to Dublin on August 20th?

Is Aer Lingus any better? Flight from Dub-Boston will be on Aer Lingus.