Kiki's apartment was a great space for our family group of 6 people. The space is large, the main beds comfortable and the kitchen is decently stocked.
The location is fantastic, only a few minute walk to golden gai and all the lights of Shinjuku. It is about a ten minute walk to the main Shinjuku station and less than that to Higashi Shinjuku metro station which has 2 metro lines for good connections to the rest of Tokyo, which is nice as to not only have to go through the main Shinjuku station. There are plenty of convenience stores close by for basic supplies, but even better is the large full service Maruetsu supermarket about 300m away for many supplies, fresh food, fruit and vegetables and great take away food.
Kiki was great to communicate with and was prompt with responding. Check in with the lockbox was easy. I would definitely stay here if in Shinjuku again.