We stayed at the apartment for 4 nights. Check-In was very easy and convenient. Also the directions were clear and we found the apartment quite easy. Interior was exactly as in the pictures and quite cozy. The bathroom was small but larger then expected.
The bed was comfy however the pillows were way to hard in our opinion and the biggest minus in this apartment is that the bed is located directly at the window to the street. This has two downsides. First is that it's a very busy street (for the whole night, there's even a fire dep very close) and it is way too loud to sleep well. Second is that this time of the year it's still quite cold in Tokyo, and at times it was freezing cold during the night. However there is air conditioning and a little heater with which you could get it quite warm surrounding the bed area. On a sidenote it's not really possible to make the room dark. You have window shades, but around them is enough room to let a whole bunch of sun in. We hadn't had a problem with it, but some people might want to now that.
Location of the apartment is OK. 10-12 minute walk to the next subway station, sounds good but got a little bothersome the last days. There is a 7eleven just across the street which is a plus. You won't find many restaurants and shops around since it's more of a residential area.
Overall we enjoyed our stay but wouldn't book this apartment again simply due to the noise at night.