We stayed for approximately 10 days. It's ok for 2 people because the only room is quite small. 4 people would be really unpractical.
Pro : close to the Kehin Tohoku Line and one station away from the Yamanote. 2 combinis within 5min walk. The room is ok, the bathroom is really nice. You have plenty of restaurant in Oji or Kawaguchi which are really close on the Kehin Tohoku line. Despite the train proximity the neighborhood is quite peacful.
cons : the toilet are small, the room lack organisation. The cleaning was not properly done (greasy burner, some hair and dust left here and there). Nothing shocking but I would expect better for the price. Also noise isolation is quite poor which mean you here footsteps/doors/etc from the whole building.
I would say it is ok for a short stay for 2 people but nothing else.