Hi, we planned on taking the train from Dublin to Galway to get to our family on Inishmaan. A family member said that the bus is the "best" way to get there, but we want to be comfortable as we will be taking a redeye from Boston, MA and landing in Dublin and heading straight to Galway to then take a flight to Inishmaan. I am traveling with my husband, 9 yr old son and 77 yr old MIL and we have never been to Ireland (my MIL has been to Ireland, but we are taking the lead on planning) Train or bus?
I think the reason your family member suggested the bus is because the bus picks you up outside the airport terminal. https://www.citylink.ie/. If you take the train you have to make your way to Dublin via taxi or bus and then get on the train.
The problem is, whether you go by train or bus, you don't know whether your flight will be on time, or how long it will take for immigration.
Then at the Galway end transfer to the airport for the flight at about 4pm.
There are a lot of moving parts in this which could go wrong.
My son, who lives in Galway, prefers the bus from the airport (https://www.citylink.ie/) as it picks you up right at the airport--no need to figure out how to get to train station in Dublin proper--and takes roughly the same amount of time. He says the bus is very nice (as nice as a train) and drops you off in the heart of Galway City. Just a perspective I thought might be helpful. Enjoy your time in Ireland!