We stayed for four nights here during the New Year weekend. Very easy to get to the celebrations at Zojo-ji. Easy walk to both Daimon subway station and Hamamatsu-cho JR station. For travelers who don't know, JR and subway are two separate transit systems, so having easy access to both is valuable for your time.
The building itself is a bit grungy, and the public areas (lobby, elevator, etc.) really need a good cleaning. However, if you could look past all that, the place works fine.
As for the apartment unit interior, the best scores go to the fact that there are two separate bedrooms. 1 with two single beds (great for kids) and another with a double (parents). On the downside, all the pillows are yellow-stained, and the cleaners appeared to ignore the edges of all the room floors (dust balls, hair, sticky spots). We found a lot of hair in the sheets and comforters, so we chose to wash them ourselves. Amenities are there, but supplies like detergent and tissues were out.