I stayed with Rafael and his family for 8 days during my time in Madrid and it was a very good experience. Throughout my whole stay, they went out of their way to make it comfortable, always ready to help.
The price is definitely a good one as well, and there's a kitchen with everything you need to cook your own meals.
Location is fine, 2 mins walk from the nearest subway and roughly 10 mins from a supermarket.
All in all, one of the best Airbnb stays I've ever had.