Yeah, they do feel similar. Dublin is much busier than Boston but they both have that lovely, Irish lack of a facade. There's little if any pretentiousness, etc. And they both have a larger city looming close enough to keep them aware of the world outside but far enough away to have little lived, daily impact. Most of the differences are mainly a result of America's social structure - for example, there are almost no homeless people on the street in Dublin.
St. John's used to feel quite a lot like Dublin too but the latter has changed and we now feel irredeemably provincial in comparison. Very comparable to Galway, though, so we've still got that.
