Thanks all. The Boston Beer Works was about the best I managed to get to in the limited time available. They had a great hoppy APA and IPA and a blueberry beer that looks like a lava lamp in a glass. The Kinsale Irish pub had a couple of nice regulars on draft (including O'Hara's stout) and some guest beers on rotation.
There is also a Boston Beer Works with limited selection in the Aer Lingus terminal at Logan, from where I am posting this. You'd never find it unless actively searching for it.