Wonderful in every way! Warm welcome while still totally private, cozy flat with everything you could need, and a fun safe neighbourhood with the T and shops in easy walking distance while still on a residential street. Getting there from the airport was a snap on the T (and only cost $2.65).
Maria Elena describes it perfectly - it's like staying with family or friends rather than in a hotel. Lots of personal touches (books, nick-nacks in the bathroom, CDs), maps and recommendations for eating and sightseeing, and everything works great - shower, wifi, comfy bed, gas stove for cooking, basic kitchen supplies provided (coffee, spices, sugar..). Feels like a home away from home. Perfect for one person or a couple who love each other! I hope it's available next time I'm in Boston.