Excellent place! I stayed in #3, which was on the third floor, during July. Air conditioning worked comfortably, allowing for a comfortable night's sleep. The room is immaculate, well appointed, and the attached bathroom is spacious. The house is centrally located, with public transportation, markets, and coffee shops within walking distance. The shared spaces (kitchen, dining room, family room) are comfortable and welcoming spaces. There were other guests staying while I was there, but I never heard them. The neighborhood is quiet and feels very safe for a single traveler. Will stay here again next time I'm in Cambridge.