Boris & Susan's place might be one of (if not THE) best place/s I've stayed with Airbnb over the years. The level of independence given to guests via access codes to the door is nice. When one arrives, the room will be sparkling clean, comfortable, and extremely welcoming -- I had an bounteous array of snacks and drinks waiting on my desk! Moreover, the rest of the property and other private rooms are also quite nice. The kitchen was a fantastic feature; there, one can find even MORE snacks and drinks after a long journey in to Boston.
I could ramble for ages, but the point is that this really is a stellar place to stay and, in my opinion, a far better option for airport runs, train access needs, and/or just plain hanging out in the city than any hotel!