Our Boston experience was tremendous, and it was in no small part because of our stay with John. Right from the start he made us feel incredibly comfortable and welcome - from meeting us at the Subway station on our arrival, to walking out with us in the evening to help orient us in the local area. We shared some great beers on his lovely outdoor space, talked about music, culture, politics, and on our last night John took us out to a local gig which he knew would interest us - something that we never would've known about otherwise.
As for the room, it was superbly comfortable - the futon gave us a couple of great nights' sleep. John was generous with breakfast options - we woke up happily every morning to the aroma of freshly-ground coffee.
The location is perfect - easy enough on the subway to downtown Boston, but close (walking distance) to other lovely areas in Cambridge/Somerville, where you'll find hip little bars and restaurants.
We would wholeheartedly recommend John's place to everyone. A warmer and more convivial host you could not hope to find. Thanks John!