I had a great stay in Málaga and would come back in an instant.
The host was very kind and gave a helpful advice: If you want to leave the luggage before the check-in (or after the check-out), there are lockers around the corner, at Calle Carretería 53.
The location of the flat is perfect for walking to the center and its sights. And even though I travelled alone, there is enough space for a couple.