Stayed 7 nights in Dec.
Location wise, the apartment was very near the metro station (less than 5 mins walk), it takes only 4 stops to reach Shinjuku, however you will have to switch trains. And to get to Shibuya it takes 30 mins, switching trains twice.
The neighbourhood was a nice quiet residential area, very safe even for a solo female traveler. There are 7-11, Matsuya (rice bowl fast food) close by.
The apartment is on the second floor with no elevator so there is a bit of lifting the luggages through very narrow stairs. The place was spacious and was sufficient for 2 adults and 2 large suitcases.
Ronny was effective and responsive in communication, I was informed early on directions to the apartment, where the heater was, wifi etc.
Ronny left us some fresh fruits and milk in the fridge when we checked in which was nice!