Our stay at Sato's place was very nice. The apartment is small but can hold many people, and check-in was easy. The location, being near Ikebukuro station, is possibly among the best in Tokyo, with a wealth of great restaurants and shopping nearby.
The only minor complaints are that the furnishings are relatively cheap and the walls are thin so the nights can be a bit noisy. This wasn't a major issue for our group.
We also had a minor issue where we accidentally stained a pillowcase but we resolved this with the host.