The place is in the perfect location. Lavapies is lively in the day and you find great places to eat and drink in the evening, without it being as noisy as the direct city center. I also felt safe alone at night as a woman. The apartement is simple, but comfortable and lovingly aranged with everything one might need. The host is super nice and her sister in law is there to welcome you and help you with any questions (she's speaking only spanish though). I stayed 3 month and there was even monthly cleaning included in the price.
One thing that was a problem for me: I happened to be in Madrid in a particularly cold spring and the place was very badly heated for my taste. There is just one portable electric heater for 2 rooms, so be prepared to bring warmer clothing in winter/spring. Otherwise I have no complaints at all. I immensely enjoyed my stay and would certainly return.