We stayed for 4 nights. The place is clean and the location is great if you want to visit Cambridge/Harvard/MIT/Boston. On the down side: it's located on a large street with lots of traffic during the day. Noise level is fine during the night.
I would not recommend booking this accommodation for more than 4 persons. We were 6. When we arrived there were no sheets and blankets for the 5th and 6th person, and we had to sleep on an air mattress with a leak, that is, we essentially slept on the ground.
The host, however, was nice and managed to fix these things quickly on request.
Overall, we can recommend the place (if you are not more than 4 people...this should really not be advertised for more than 4).