This is more a room in a hotel than an apartment. There was desk staff almost 24/7 which was nice, and they spoke great English so checking in and overall communication was great. Unfortunately our room was right in front of check in desk so we had conversations outside the room at all hours. Also, the room itself was very bare bones and was honestly quite underwhelming inside with only just the bare essentials. Barely enough pillows, wifi that we leeched from the next room, etc.
We don't have experience with other accommodation in Tokyo so it's hard to know how it compares, but we were not particularly impressed.
Either way we weren't in Tokyo to stay inside an apartment but to experience the city itself. The location of the hotel is amazing, super close to a metro stop and an easy walk to the main parts of Shinjuku. Overall we were happy here but would probably look elsewhere for our next stay in Shinjuku.