John and Kay's bed and breakfast was ok, but I would suggest other listings if you have flexibility with the date and time of your stay in Boston.
While the pictures were mostly accurate to what it was like when we arrived, there were some areas that left me uncomfortable.
1) The house on the first, second and third floor, bathrooms and bedrooms all had an odd smell. It didn't help that it was extremely humid so the smell was elevated to another level. Even with the window AC unit turned on all day long, our room still smelled. In August weather the AC was needed, but when it got too cold at night, we couldn't turn the AC off because the room smelled so much we needed fresh circulating air.
2) The sheets, pillows and towels had some stains on it. I'm not sure if it was blood or dirt, but there were faint stains that made me feel uneasy. I normally pack my own towels, but this time I didn't and I definitely regret it. Linens, pillows and towels should always be fresh and/or new. Otherwise stains can make the guests feel uneasy with the cleanliness.
3) The second floor bathroom was not clean and there was no hand soap. It was surprising because we are in a pandemic so I expected there to at least be the basic essentials. There was also mold and a weird smell too.
Besides those three points, John and Kay's listing was good enough. John was friendly and waited for us to open the door shortly after we arrived. The house is also close to the #9 bus (literally 1 min walk to the corner) which you can take to the Red Line Broadway station in 10 min and go basically anywhere in Boston.
Overall I would recommend this place only if location is really important to you. It's safe and close to public transpo, but otherwise I would say look elsewhere. The old fashion interior is amazing, but it wasn't that clean, especially the bathrooms, so I would much rather go with a modern place instead.
Oh and John does serve breakfast every day. We skipped it to try local restaurants, but if you want a true bed and breakfast experience, you certainly could do that with John.