Hard to find many faults here, the apartment was nice, clean and comfortable, relatively spacious, had everything we needed, communication was superb, check in & out very easy, and location is good. The street is very quiet so great for sleeping, there is a 24hr supermarket 1 minute away and the metro station is 2 mins away, really easy and convenient to get everywhere we wanted to, except perhaps the airport which required a few changes (which when we had just arrived was a bit confusing). Shinjukuchome is just a short walk away (less than 10mins) which has loads of bars & restaurants, the gay scene and a great super mario themed bar.
We only cooked breakfast and not anything else so I can't comment beyond that, but that's all we needed and it worked well for us.
Really the apartment is perfect for 4: 2 in the bedroom and 2 in the common area but round a corner so semi private. We were 5 and the 3rd bed (in common area) didn't have a proper mattress so was less comfortable. It is up a few flights of stairs which was only an issue with cases on arrival. If you are sensitive to light bring an eye mask as the curtains are light.
All in all I would definitely recommend, we had a great stay. thank you!