Stayed at the apartment for 5 nights. I had some difficulty in finding the place at first despite a very comprehensive set of instructions given by the host (just my issue).
Check-in was done via real-time video call. There was some lagging but the process was fast enough and the operator was very friendly.
The place was indeed quite small, which wasn’t much of a problem for me because I was a petite person and also travelling solo, but if you’re taller/larger/have more than a piece of luggage or travelling in a pair you might want to reconsider. It was nonetheless very clean.
Location was superb. Just a 3-minute walk from Ookubo Station and a further 5-minute walk from Shin-Ookubo Station (JR Yamanote Line), both just one station away from Shinjuku. The area was away from all the buzz at Shinjuku but you can still find quite a lot of supermarkets, convenience stores, restaurants and pharmacies within minutes of walking (there’s even a Don Quixote shop nearby!).